Abstract Title:
Effects of Citrulline Supplementation on Exercise Performance in Humans: A Review of the Current Literature.
Abstract Source:
J Strength Cond Res. 2020 Jan 22. Epub 2020 Jan 22. PMID: 31977835
Abstract Author(s):
Adam M Gonzalez, Eric T Trexler
Article Affiliation:
Adam M Gonzalez
Abstract:
Gonzalez, AM and Trexler, ET. Effects of citrulline supplementation on exercise performance in humans: A review of the current literature. J Strength Cond Res XX(X): 000-000, 2020-L-citrulline, a nonessential amino acid found primarily in watermelon, has recently garnered much attention for its potential to augment L-arginine bioavailability, nitric oxide production, and exercise performance. Over the past decade, L-citrulline has received considerable scientific attention examining potentially ergogenic properties for both aerobic and anaerobic exercise performance. Thus, the purpose of this article is to summarize the theoretical rationale behind L-citrulline supplementation and to comprehensively review the available scientific evidence assessing the potential ergogenic value of L-citrulline supplementation on vascular function and exercise performance in humans. In addition, research that has investigated the potential synergistic effects of L-citrulline with other dietary ingredients (e.g., arginine, antioxidants, nitrates, and branched-chain amino acids) is reviewed. Oral L-citrulline and citrulline malate supplementation have shown to increase plasma citrulline and arginine concentrations, along with total nitrate and nitrite concentrations. Although blood flow enhancement is a proposed mechanism for the ergogenic potential of L-citrulline, evidence supporting acute improvements in vasodilation and skeletal muscle tissue perfusion after supplementation is scarce and inconsistent. Nevertheless, several studies have reported that L-citrulline supplementation can enhance exercise performance and recovery. Given the positive effects observed from some investigations, future studies should continue to investigate the effects of both acute and chronic supplementation with L-citrulline and citrulline malate on markers of blood flow and exercise performance and should seek to elucidate the mechanism underlying such effects.
Article Published Date : Jan 21, 2020
Abstract Title:
Is mode of transport to work associated with mortality in the working-age population? Repeated census-cohort studies in New Zealand 1996, 2001 and 2006.
Abstract Source:
Int J Epidemiol. 2020 Jan 13. Epub 2020 Jan 13. PMID: 31930316
Abstract Author(s):
Caroline Shaw, Tony Blakely, June Atkinson, Alistair Woodward
Article Affiliation:
Caroline Shaw
Abstract:
BACKGROUND: Increasing active transport is proposed as a means to address both health and environmental issues. However, the associations between specific modes, such as cycling, walking and public transport, and health outcomes remain unclear. We examined the association between mode of travel to work and mortality.
METHODS: Cohort studies of the entire New Zealand working population were created using 1996, 2001 and 2006 censuses linked to mortality data. Mode of travel to work was that reported on census day, and causes of death examined were ischaemic heart disease and injury. Main analyses were Poisson regression models adjusted for socio-demographics. Sensitivity analyses included: additional adjustment for smoking in the 1996 and 2006 cohorts, and bias analysis about non-differential misclassification of cycling vs car use.
RESULTS: Walking (5%) and cycling (3%) to work were uncommon. Compared with people reporting using motor vehicles to travel to work, those cycling had a reduced all-cause mortality (ACM) in the socio-demographic adjusted models RR 0.87 (0.77-0.98). Those walking (0.97, 0.90-1.04) and taking public transport (0.96, 0.88-1.05) had no substantive difference in ACM. No mode of transport was associated with detectable statistically significant reductions in cause-specific mortality. Sensitivity analyses found weaker associations when adjusting for smoking and stronger associations correcting for likely non-differential misclassification of cycling.
CONCLUSIONS: This large cohort study supports an association between cycling to work and reduced ACM, but found no association for walking or public-transport use and imprecise cause-specific mortality patterns.
Article Published Date : Jan 12, 2020
Abstract Title:
Cycle Training improves vascular function and neuropathic symptoms in patients with type 2 diabetes and peripheral neuropathy: A randomized controlled trial.
Abstract Source:
Exp Gerontol. 2019 Dec 31 ;131:110799. Epub 2019 Dec 31. PMID: 31899340
Abstract Author(s):
Farhad Gholami, Hamieh Nazari, Milad Alimi
Article Affiliation:
Farhad Gholami
Abstract:
Diabetic peripheral neuropathy (DPN) is associated with peripheral arterial disease and endothelial dysfunction. We investigated the effect of exercise training on the measures of superficial femoral artery (SFA) and neuropathic symptoms in patients with DPN. In a randomized-controlled trial, 31 volunteers with established DPN were randomly assigned to experimental or control groups. Experimental group performed cycling exercise training (50%-70% of heart rate reserve, 30-45 min, 3 sessions/week) over 12 weeks. Before and 48 h after the experimental period a 5-min flow mediated dilation (FMD) response in SFA using Color Doppler Ultrasonography, fasting glucose level, HbA1c and neuropathic score were assessed. FMD% significantly increased in the experimental group (from 3.2 ± 1.1% to 5.7 ± 1.2%) compared to the control condition (P = 0.0001). However, no significant alteration occurred in baseline membrane diameter and intima media thickness (P > 0.05). We also observed a significant improvement in fasting glucose, HbA1c and Michigan Diabetic Neuropathy Score (MDNS) following exercise intervention (all P < 0.05). Linear regression analysis indicated that the change in MDNS was significantly associated with the change in HbA1c (R Square = 0.34, standardized coefficients Beta = -0.58, P = .001) and FMD (R Square = 0.37, standardized coefficients Beta = 0.61, P = .001). This finding may beclinically of considerable importance as metabolic and vascular factors have been indicated to be involved in the development of DPN.
Article Published Date : Dec 30, 2019
Abstract Title:
Mixed Flavonoid Supplementation Attenuates Postexercise Plasma Levels of 4-Hydroxynonenal and Protein Carbonyls in Endurance Athletes.
Abstract Source:
Int J Sport Nutr Exerc Metab. 2019 Nov 21:1-8. Epub 2019 Nov 21. PMID: 31754080
Abstract Author(s):
David C Nieman, Giuseppe Valacchi, Laurel M Wentz, Francesca Ferrara, Alessandra Pecorelli, Brittany Woodby, Camila A Sakaguchi, Andrew Simonson
Article Affiliation:
David C Nieman
Abstract:
This double-blinded, placebo controlled, randomized crossover trial investigated the influence of 2-week mixed flavonoid versus placebo supplementation on oxinflammation markers after a 75-km cycling time trial in 22 cyclists (42.3± 1.7 years). Blood samples were collected before and after the 2-week supplementation, and then 0 hr, 1.5 hr, and 21 hr post 75-km cycling (176 ± 5.4 min, 73.4 ±2.0% maximal oxygen consumption). The supplement provided 678-mg flavonoids with quercetin (200 mg), green tea catechins (368 mg, 180-mg epigallocatechin gallate), and anthocyanins (128 mg) from bilberry extract, with caffeine, vitamin C, and omega-3 fatty acids added as adjuvants. Blood samples were analyzed for blood leukocyte counts, oxinflammation biomarkers, including 4-hydroxynonenal, protein carbonyls, and peripheralblood mononuclear mRNA expression for cyclooxygenease-2 and glutathione peroxidase. Each of the blood biomarkers was elevated postexercise (time effects, all ps<.01), with lower plasma levels for 4-hydroxynonenal (at 21-hr postexercise) in flavonoid versus placebo (interaction effect, p = .008). Although elevated postexercise, no trial differences for the neutrophil/lymphocyte ratio (p = .539) or peripheral blood mononuclear mRNA expression for cyclooxygenease-2 (p = .322) or glutathione peroxidase (p = .839) were shown. Flavonoid supplementation prior to intensive exercise decreased plasma peroxidation and oxidative damage, as determined by 4-hydroxynonenal. Postexercise increases were similar between the flavonoid and placebo trials for peripheral blood mononuclear mRNA expression for cyclooxygenease-2 and the nuclear factor erythroid 2-related factor 2 related gene glutathione peroxidase (NFE2L2). The data support the strategy of flavonoid supplementation to mitigate postexercise oxidative stress in endurance athletes.
Article Published Date : Nov 20, 2019
Abstract Title:
Outdoor cycling improves clinical symptoms, cognition and objectively measured physical activity in patients with schizophrenia: A randomized controlled trial.
Abstract Source:
J Psychiatr Res. 2019 Oct 21 ;120:144-153. Epub 2019 Oct 21. PMID: 31678749
Abstract Author(s):
Jehkwang Ryu, Jae Hoon Jung, Jiheon Kim, Chan-Hyung Kim, Hwa-Bock Lee, Do-Hoon Kim, Sang-Kyu Lee, Ji-Hyeon Shin, Daeyoung Roh
Article Affiliation:
Jehkwang Ryu
Abstract:
PURPOSE: The therapeutic effects of outdoor cycling (OC) and its benefits on physical activity (PA) were investigated in people with schizophrenia.
METHODS: Sixty patients with schizophrenia were randomly assigned to 16-weeks of Outdoor Cycling (OC) (n = 30, 50% male; mean age, 38.7 ± 10.1) or Occupational Therapy (OT) (n = 30, 50% male; mean age, 39.0 ± 8.6). OC and OT involved one 90-min group session per week. OC consisted of structured exercise programs and OT addressed daily living skills. Primary outcome measurements weremental health variables, such as Brief Psychiatric Rating Scale, Beck's Depression Inventory, State and Trait Anxiety Inventory, Rosenberg Self-Esteem Scale, Global Assessment of Functioning and executive function (Wisconsin Card Sorting Test, WCST). Secondary measures were the adherence and PA. PAwas measured by responding to the Physical Activity Scale (K-PASE) and wearing a pedometer for 2 days.
RESULTS: Repeated measures ANOVA revealed improved psychotic symptoms (p = .014), depression (p = .007), state (p = .031) and trait anxiety (p = .002) and global functions (p = .024) in the OC group compared with OT group. The OC group showed increased correct rates (p = .022) and categories completed (p = .033) in the WCST. There was no difference in total K-PASE score between groups; however, there was a significant improvement in the number of daily steps in the OC group compared with the OT group (p = .030).
CONCLUSION: OC significantly improved mental health and executive function in individuals with schizophrenia. Further, OC significantly increased PA measured by the pedometers. These findings suggest that OC offers a safe and attrition-lowering intervention promoting mental health and PA.
TRIAL REGISTRATION: cris.nih.go.kr identifier: KCT-0000873.
Article Published Date : Oct 20, 2019
Abstract Title:
Bicycle exercise training improves ambulation in patients with peripheral artery disease.
Abstract Source:
J Vasc Surg. 2019 Sep 5. Epub 2019 Sep 5. PMID: 31495679
Abstract Author(s):
Makoto Haga, Katsuyuki Hoshina, Hiroyuki Koyama, Tetsuro Miyata, Yosuke Ikegami, Akihiko Murai, Yoshihiko Nakamura
Article Affiliation:
Makoto Haga
Abstract:
OBJECTIVE: Exercise training has multiple beneficial effects in patients with arteriosclerotic diseases; however, the exact underlying mechanisms of the effects are not completely understood. This study aimed to evaluate the effectiveness of a supervised exercise program in improving gait parameters, including the variability and walking performance of lower limb movements, in patients with peripheral artery disease (PAD) and intermittent claudication (IC).
METHODS: Sixteen patients with a history of PAD and IC were recruited for this study, and they completed a 3-month supervised bicycle exercise program. The ankle-brachial index and responses to quality of life (QOL) questionnaires were evaluated. Near-infrared spectroscopy was also performed to determine the hemoglobin oxygen saturation in the calf. Patients' kinematics and dynamics, including joint range of motion and muscle tension, were evaluated using an optical motion capture system. Computed tomography images of each muscle were assessed by manual outlining. Data were collected before and after the supervised bicycle exercise program, and differences were analyzed.
RESULTS: Significant differences were not found in step length, ankle-brachial index, and hemoglobin oxygen saturation before and after the supervised bicycle exercise program; however, IC distance (P = .034), maximum walking distance (P = .006), and all QOL questionnaire scores (P <.001) showed significant improvement. Hip range of motion (P = .035), maximum hip joint torque (right, P = .031; left, P = .044), maximum tension of the gluteus maximus muscle (right, P = .044; left, P = .042), and maximum hip joint work (right, P = .048; left, P = .043) also significantly decreased bilaterally. Computed tomography images showed a significant increase in the cross-sectional area of the abdominal, trunk, and thigh muscles but not in that of the lower leg muscles after the supervised exercise program intervention.
CONCLUSIONS: In this study, bicycle exercise training improved the QOL and walking distance and decreased hip movement. The results showed that bicycling might be as useful as walking in patients with PAD.
Article Published Date : Sep 04, 2019
Abstract Title:
Health Benefits of Indoor Cycling: A Systematic Review.
Abstract Source:
Medicina (Kaunas). 2019 Aug 8 ;55(8). Epub 2019 Aug 8. PMID: 31443139
Abstract Author(s):
Manuel Chavarrias, Jorge Carlos-Vivas, Daniel Collado-Mateo, Jorge Pérez-Gómez
Article Affiliation:
Manuel Chavarrias
Abstract:
Indoor cycling is one of the most practiced activities in fitness centers for most people regardless of their physical conditioning level. Several studies have analyzed the effect of indoor cycling on several parameters related to health, such as maximal oxygen consumption, blood pressure, body composition, as well as biochemical markers such as HDL or LDL. However, no study has synthesized all health benefits associated with the indoor cycling practice in the form of a systematic review and established guidelines or recommendations. Therefore, the aim of this manuscript was to conduct a systematic review of published studies about the benefits of indoor cycling training and to establish recommendations for coaches, researchers, and practitioners.The PRISMA guidelines were followed to conduct the current systematic review. A systematic search was performed to retrieve relevant published articles until January 2019 using the following keywords: 'indoor cycling', 'indoor bicycle', and 'spinning exercise'. Information about participants, intervention, comparisons, outcomes, and study design (PICOS) was extracted.A total of 300 studies were initially identified. After the revision process, 13 of them were included. The total sample size of the studies was 372 (306 women). Results revealed that indoor cycling may improve aerobic capacity, blood pressure, lipid profile, and body composition. These enhancements may be achieved as standalone intervention or combined with other physical exercises or diet.The combination of indoor cycling and diet is recommended to improve the lipid profile, lose weight, and reduce blood pressure. Furthermore, indoor cycling alone may also enhance aerobic capacity. Given the lack of randomized controlled trials, these conclusions should be taken with caution.
Article Published Date : Aug 07, 2019
Abstract Title:
The Effect of Cycling Through a Projection-Based Virtual Environment System on Generalized Anxiety Disorder.
Abstract Source:
J Clin Med. 2019 Jul 4 ;8(7). Epub 2019 Jul 4. PMID: 31277466
Abstract Author(s):
Tsai-Chiao Wang, Chia-Liang Tsai, Ta-Wei Tang, Wei-Li Wang, Kuan-Ting Lee
Article Affiliation:
Tsai-Chiao Wang
Abstract:
Virtual reality (VR) has the potential to help clinical medicine manage generalized anxiety disorder (GAD). However, patients with GAD who use traditional head-mounted VR to cycle may cause them to feel motion sickness and fatigue. To solve this problem, a projection-based virtual environment (VE) system was built to provide GAD patients with a sense of immersion while they are cycling. This projection-based VE system allows patients with GAD to interact with the virtual environment and produce experiences similar to cycling in the outdoors. Sixty GAD patients met several screening criteria and were selected as participants. All participants were randomly assigned to one of the two 20-min conditions: (1) Observing watercolor paintings projected by the projector while engaged in cycling with a stationary bicycle; or (2) observing the scenes (i.e., forest or park) projected by the VE system and engaging in cycling with a stationary bicycle. Finally, this study confirmed that patients with GAD in the projection-based VE group exhibited higher alpha values and lower galvanic skin responses (GSR) after cycling than those cycling in the control group. These results showed that cycling in the projection-based VE group allowed the patient with GAD to achieve higher exercise intensity and lower perceived emotional stress.
Article Published Date : Jul 03, 2019
Abstract Title:
Cycling is associated with a lower incidence of cardiovascular diseases and death: Part 1 - systematic review of cohort studies with meta-analysis.
Abstract Source:
Br J Sports Med. 2019 Jul ;53(14):870-878. Epub 2019 May 31. PMID: 31151937
Abstract Author(s):
Solveig Nordengen, Lars Bo Andersen, Ane K Solbraa, Amund Riiser
Article Affiliation:
Solveig Nordengen
Abstract:
OBJECTIVES: Physical inactivity is a risk factor for cardiovascular disease (CVD). Cycling as a physical activity holds great potential to prevent CVD. We aimed to determine whether cycling reduces the risk of CVD and CVD risk factors and to investigate potential dose-response relationships.
DESIGN: Systematic review and meta-analysis of quantitative studies.
ELIGIBILITY CRITERIA FOR SELECTING STUDIES: We searched four databases (Web of Science, MEDLINE, SPORTDiscus and Scopus). All quantitative studies, published until August 2017, were included when a general population was investigated, cycling was assessed either in total or as a transportation mode, and CVD incidence, mortality or risk factors were reported. Studies were excluded when they reported continuous outcomes or when cycling and walking were combined in them. We pooled adjusted relative risks (RR) and OR. Heterogeneity was investigated using I.
RESULTS: The search yielded 5174 studies; 21 studies which included 1,069,034 individuals. We found a significantly lower association in combined CVD incidence, mortality and physiological risk factors with total effect estimate 0.78 (95% CI (CI): 0.74-0.82; P<0.001; I=58%). Separate analyses for CVD incidence, mortality and risk factors showed estimates of RR 0.84 (CI, 0.80 to 0.88; P<0.001; I=29%), RR 0.83 (CI, 0.76 to 0.90; P<0.001; I=0%), and OR 0.75 (CI, 0.69 to 0.82; P<0.001; I=66%), respectively. We found no dose-response relationship or sex-specific difference.
CONCLUSIONS: Any form of cycling seems to be associated with lower CVD risk, and thus, we recommend cycling as a health-enhancing physical activity.
SYSTEMATIC REVIEW REGISTRATION: Prospero CRD42016052421.
Article Published Date : Jun 30, 2019
Abstract Title:
Cycling and cardiovascular disease risk factors including body composition, blood lipids and cardiorespiratory fitness analysed as continuous variables: Part 2-systematic review with meta-analysis.
Abstract Source:
Br J Sports Med. 2019 Jul ;53(14):879-885. Epub 2019 May 31. PMID: 31151938
Abstract Author(s):
Solveig Nordengen, Lars Bo Andersen, Ane K Solbraa, Amund Riiser
Article Affiliation:
Solveig Nordengen
Abstract:
OBJECTIVES: We aimed to examine the relationship between cycling (particularly commuter cycling) and risk factors associated with cardiovascular diseases (CVDs) including body composition, blood lipids and cardiorespiratory fitness. This study differed from our recent (Part 1) systematic review in that risk factors for CVD were analysed as continuous variables rather than being present or absent.
DESIGN: Systematic review and meta-analysis.
ELIGIBILITY CRITERIA: We searched four databases (Web of Science, MEDLINE, SPORTDiscus and Scopus). All quantitative studies, published until August 2017, were included when a general population was investigated, cycling was assessed either in total or as a transportation mode, and CVD risk factors were reported.
METHODS: We analysed body composition, physical activity (PA), cardiorespiratory fitness (CRF), blood lipids and blood pressure (BP). Skinfold, waist circumference and body mass index were analysed and prioritised in that order when more than one measure were available. PA included measures of counts per minutes, moderate-to-vigorous PA or minutes per week. CRF included results of maximal tests with or without expired air or submaximal test. For blood lipids and BP, separate analyses were run for low-density and high-density lipoprotein, triglycerides, total cholesterol, systolic BP and diastolic BP. Studies were excluded when reporting dichotomous outcomes or when cycling and walking were combined. Heterogeneity was investigated using I.
RESULTS: Fifteen studies were included; the majority reported commuter cycling. In total, we included 5775 cyclists and 39 273 non-cyclists. Cyclists had more favourable risk factor levels in body composition -0.08 (95% CI -0.13 to -0.04), PA 0.13 (95% CI 0.06 to 0.20), CRF 0.28 (95% CI 0.22 to 0.35) and blood lipids compared with non-cyclists. There was no sex difference in risk reduction.
CONCLUSION/IMPLICATION: Cycling mitigated the risk factor profile for CVD. A strength of this systematic review is that all the risk factors were analysed as continuous variables. These data provide evidence for practitioners, stakeholders, policy-makers and city planners to accommodate and promote cycling.
SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42016052421.
Article Published Date : Jun 30, 2019
Abstract Title:
Pomegranate Extract Improves Maximal Performance of Trained Cyclists after an Exhausting Endurance Trial: A Randomised Controlled Trial.
Abstract Source:
Nutrients. 2019 Mar 28 ;11(4). Epub 2019 Mar 28. PMID: 30925733
Abstract Author(s):
Antonio Torregrosa-García, Vicente Ávila-Gandía, Antonio J Luque-Rubia, María Salud Abellán-Ruiz, María Querol-Calderón, F Javier López-Román
Article Affiliation:
Antonio Torregrosa-García
Abstract:
The efficacy of pomegranate () extract (PE) for improving performance and post-exercise recovery in an active population was equivocal in previous studies. In this study, a randomised, double-blinded, placebo-controlled, balanced, cross-over trial with two arms was conducted. Eligibility criteria for participants were as follows: male, amateur cyclist, with a training routine of 2 to 4 sessions per week (at least one hour per session). The cyclists (= 26) were divided into treatment (PE) and placebo (PLA) groups for a period of 15 days. After physical tests, the groups were exchanged after a 14-day washout period. Exercise tests consisted of endurance bouts (square-wave endurance exercise test followed by an incremental exercise test to exhaustion) and an eccentric exercise drill. The objective was to assess the efficacy of PE in performance outcomes and post-exercise muscular recovery and force restoration after a prolonged submaximal effort. Twenty-six participants were included for statistical analysis. There was a statistically significant difference in total time to exhaustion (TTE)(17.66⁻170.94 s,<0.02) and the time to reach ventilatory threshold 2 (VT2)(26.98⁻82.55 s,<0.001), with greater values for the PE compared to the PLA group. No significant results were obtained for force restoration in the isokinetic unilateral low limb test. PE, after a prolonged submaximal effort, may be effective in improving performance outcomes at maximal effort and might help to restore force in the damaged muscles.
Article Published Date : Mar 27, 2019
Abstract Title:
Ergometer cycling improves the ambulatory function and cardiovascular fitness of stroke patients-a randomized controlled trial.
Abstract Source:
J Phys Ther Sci. 2019 Mar ;31(3):211-216. Epub 2019 Mar 19. PMID: 30936633
Abstract Author(s):
Ernest Kwesi Ofori, Emmanuel Frimpong, Adeolu Ademiluyi, Olajide Ayinla Olawale
Article Affiliation:
Ernest Kwesi Ofori
Abstract:
[Purpose] The aim of this study was to assess the effects of ergometer cycling on the ambulatory function and cardiovascular fitness of patients with stroke in the sub-acute phase. [Participants and Methods] Twenty (20) patients with stroke in the sub-acute phase were randomly allocated to either an ergometer cycling group (n=10) or a control group (n=10). The experimental (ergometer cycling) group performed cycling exercises in addition to conventional physiotherapy for 60 minutes per session, three times per week for 8 weeks. The control group only received conventional physiotherapy for the same duration as the experimental group. Assessments of participants' functional ambulatory category, ambulatory velocity, 6-minute walk test, heart rate and blood pressure were conducted at baseline and at the end of the 8-week intervention. [Results] The means of the ambulatory velocity and distance walked in 6 minutes were significantly higher in the ergometer cycling group than those of the control group at week 8. However, the increase in the FAC score was not significant. The means of heart rate, systolic and diastolic blood pressures significantly decreased in the ergometer cycling group compared to the control group at the end of the 8-week of intervention. [Conclusion] This study demonstrated that ergometer cycling improved the ambulatory function and cardiovascular fitness of patients with stroke in the sub-acute phase.
Article Published Date : Feb 28, 2019
Abstract Title:
The effect of cycling on cognitive function and well-being in older adults.
Abstract Source:
PLoS One. 2019 ;14(2):e0211779. Epub 2019 Feb 20. PMID: 30785893
Abstract Author(s):
Louise-Ann Leyland, Ben Spencer, Nick Beale, Tim Jones, Carien M van Reekum
Article Affiliation:
Louise-Ann Leyland
Abstract:
It has been demonstrated that, on their own, both exercise and stimulation from the environment can improve cognitive function and well-being in older adults. The combined effect of exercising in the outdoor environment on psychological function is less well studied. The aim of the current study was to investigate the effect of an outdoor cycling intervention on cognitive function and mental health and well-being in older adults. A total of 100 older adults took part in the study (aged 50-83), 26 of which were non-cycling controls, 36 were conventional pedal cyclists and 38 were participants using an e-bike (a bike fitted with an electric motor to provide assistance with pedaling), as part of a larger project (www.cycleboom.org). Participants took part in the study for an eight-week period, with cycling participants required to cycle at least three times a week for thirty minutes in duration for each cycle ride. Cognitive function and well-being were measured before and after the intervention period. For executive function, namely inhibition (the Stroop task) and updating (Letter Updating Task), both cycling groups improved in accuracy after the intervention compared to non-cycling control participants. E-bike participants also improved in processing speed (reaction times in go trials of the Stop-It task) after the intervention compared to non-cycling control participants. Finally, e-bike participants improved in their mental health score after the intervention compared to non-cycling controls as measured by the SF-36. This suggests that there may be an impact of exercising in the environment on executive function and mental health. Importantly, we showed a similar (sometimes larger) effect for the e-bike group compared to the pedal cyclists. This suggests that it is not just the physical activity component of cycling that is having an influence. Both pedal cycles and e-bikes can enable increased physical activity and engagement with the outdoor environment with e-bikes potentially providing greater benefits.
Article Published Date : Dec 31, 2018
Abstract Title:
Effects of Beetroot Juice Supplementation on Performance and Fatigue in a 30-s All-Out Sprint Exercise: A Randomized, Double-Blind Cross-Over Study.
Abstract Source:
Nutrients. 2018 Sep 4 ;10(9). Epub 2018 Sep 4. PMID: 30181436
Abstract Author(s):
Eduardo Cuenca, Pablo Jodra, Alberto Pérez-López, Liliana G González-Rodríguez, Sandro Fernandes da Silva, Pablo Veiga-Herreros, Raúl Domínguez
Article Affiliation:
Eduardo Cuenca
Abstract:
As a nitric oxide precursor, beetroot juice (BJ) is known to enhance high-intensity exercise performance (80⁻100% VO) yet its impacts on higher intensity sprint exercise (>100% VO) remain to be established. This study sought to examine the effects of BJ supplementation on performance and subsequent fatigue during an all-out sprint exercise. Using a randomized cross-over, double-blind, placebo-controlled design, 15 healthy resistance-trained men (22.4± 1.6 years) ingested 70 mL of either BJ or placebo. Three hours later, participants undertook a 30-s all-out Wingate test. Before and after the sprint exercise and at 30 s and 180 s post-exercise, three countermovement jumps (CMJ) were performed and blood lactate samples were obtained. Compared toplacebo, BJ consumption improved peak (placebo vs. BJ, 848 ± 134 vs. 881 ± 135 W;= 0.049) and mean (641± 91 vs. 666 ± 100 W;= 0.023) power output and also reduced the time taken to reach Win the Wingate test (8.9± 1.4 vs. 7.3 ± 0.9 s;= 0.003). No differences were detected in the fatigue index. In addition, while over time CMJ height and power diminished (ANOVA<0.001) and blood lactate levels increased (ANOVA<0.001), no supplementation effect was observed. Our findings indicate that while BJ supplementation improved performance at the 30-s cycling sprint, this improvement was not accompanied by differences in fatigue during or after this type of exercise.
Article Published Date : Sep 03, 2018
Abstract Title:
Potential of electric bicycles to improve the health of people with Type 2 diabetes: a feasibility study.
Abstract Source:
Diabet Med. 2018 May 8. Epub 2018 May 8. PMID: 29738609
Abstract Author(s):
A R Cooper, B Tibbitts, C England, D Procter, A Searle, S J Sebire, E Ranger, A S Page
Article Affiliation:
A R Cooper
Abstract:
AIM: To explore in a feasibility study whether 'e-cycling' was acceptable to, and could potentially improve the health of, people with Type 2 diabetes.
METHODS: Twenty people with Type 2 diabetes were recruited and provided with an electric bicycle for 20 weeks. Participants completed a submaximal fitness test at baseline and follow-up to measure predicted maximal aerobic power, and semi-structured interviews were conducted to assess the acceptability of using an electric bicycle. Participants wore a heart rate monitor and a Global Positioning System (GPS) receiver in the first week of electric bicycle use to measure their heart-rate during e-cycling.
RESULTS: Eighteen participants completed the study, cycling a median (interquartile range) of 21.4 (5.5-37.7) km per week. Predicted maximal aerobic power increased by 10.9%. Heart rate during electric bicycle journeys was 74.7% of maximum, compared with 64.3% of maximum when walking. Participants used the electric bicycles for commuting, shopping and recreation, and expressed how the electric bicycle helped them to overcome barriers to active travel/cycling, such as hills. Fourteen participants purchased an electric bicycle on study completion.
CONCLUSIONS: There was evidence that e-cycling was acceptable, could increase fitness and elicited a heart rate that may lead to improvements in cardiometabolic risk factors in this population. Electric bicycles have potential as a health-improving intervention in people with Type 2 diabetes.
Article Published Date : May 07, 2018
Abstract Title:
Metabolic and Performance Effects of Yerba Mate on Well-trained Cyclists.
Abstract Source:
Med Sci Sports Exerc. 2018 Apr ;50(4):817-826. PMID: 29117073
Abstract Author(s):
Jose L Areta, Ingvild Austarheim, Helle Wangensteen, Carlo Capelli
Article Affiliation:
Jose L Areta
Abstract:
INTRODUCTION: Yerba Mate (YM) is a South American plant, rich in polyphenols, saponins, and xanthines, of growing scientific interest because of its metabolic effects. YM has been shown to increase fat utilization during exercise in untrained humans, but its effects on well-trained individuals during exercise are unknown.
METHODS: We characterized metabolic and physical performance effects of YM in 11 well-trained male cyclists. In a double-blind crossover design, participants ingested 5 g of YM or placebo (PL; maltodextrin) daily for 5 d and 1 h before experimental trials.
RESULTS: Ergometer-based tests included a submaximal step test (SST) at 30%-80% of V˙O2max (6 × 5-min stages), followed by a cycloergometer-based time trial (TT) test to complete mechanical work (~30 min; n = 9). Before and during tests, blood and respiratory gas samples were collected. YM increased resting plasma adrenaline concentration (P = 0.002), and fat utilization by 23% at 30%-50% V˙O2max versus PL (Glass effect sizes (ES) ± 95% confidence interval (CI), 0.8 ± 0.55) correlating strongly with post-SST plasma (glycerol; r = 0.758). Treatment effects on rates of perceived exertion, heart rate, and gross efficiency were unclear during SST. Respiratory exchange ratioduring TT indicated carbohydrate dependence and did not differ between treatments (PL, 0.95 ± 0.03 (SD); YM, 0.95 ± 0.02). TT performance showed a small (ES = 0.38 ± 0.33) but significant (P = 0.0278) improvement with YM (PL, 30.1 ± 1.8 min (SD); YM, 29.4 ± 1.4 min; 2.2% ± 2% (95% CI)), with an average increase of 7-W power output (ES = 0.2 ± 0.19; P = 0.0418; 2.3% ± 2% (95% CI)) and 2.8% V˙O2 (P = 0.019). Pacing displayed lower power output after 30% of total TT workload in PL vs YM.
CONCLUSIONS: YM increased fat utilization during submaximal exercise and improved TT performance, but performance-enhancement effect was unrelated to measures of substrate metabolism during maximal exercise.
Article Published Date : Mar 31, 2018
Abstract Title:
Effect of dietary nitrate supplementation on thermoregulatory and cardiovascular responses to submaximal cycling in the heat.
Abstract Source:
Eur J Appl Physiol. 2018 Mar ;118(3):657-668. Epub 2018 Jan 22. PMID: 29356948
Abstract Author(s):
Georgina L Kent, Brian Dawson, Gregory R Cox, Chris R Abbiss, Kurt J Smith, Kevin D Croft, Zi Xiang Lim, Annette Eastwood, Louise M Burke, Peter Peeling
Article Affiliation:
Georgina L Kent
Abstract:
PURPOSE: This study investigated whether reported improvements in blood flow distribution, and the possible related effects on thermoregulation during exercise following supplementation with beetroot juice (BR), a rich source of dietary nitrate (NO), are mitigated in the heat.
METHODS: 12 male endurance-trained cyclists (age 27 ± 6 years, VO68.6 ± 8.1 ml kg min) completed two 60 min submaximal cycling trials at 60% of VOpower output. Trials were performed in hot environmental conditions (33.3 ± 0.4 °C, 48.8 ± 3.0% RH) following 3 days of supplementation with either NO-rich BR (6.5 mmol NOfor 2 days and 13 mmol NOon the final day) or NO-depleted placebo (PLA). Salivary NOand nitrite (NO) were measured before and after the supplementation period. During exercise, cutaneous blood flow, blood pressure (MAP), core temperature (T), mean skin temperature (T), indices of muscle oxygenation and oxygen (O) consumption were measured.
RESULTS: Salivary NOand NOincreased significantly following BR by 680 and 890%, respectively. There were no significant differences observed for cutaneous blood flow, MAP, T, T, muscle oxygenation, or Oconsumption between BR and PLA.
CONCLUSION: This investigation shows that the ergogenic effects and health benefits of BR supplementation, such as augmented cutaneous blood flow, reduced MAP, increased muscle oxygenation, and improved aerobic efficiency may be attenuated when exercise is performed in hot conditions.
Article Published Date : Feb 28, 2018
Abstract Title:
Health benefits of electrically-assisted cycling: a systematic review.
Abstract Source:
Int J Behav Nutr Phys Act. 2018 11 21 ;15(1):116. Epub 2018 Nov 21. PMID: 30463581
Abstract Author(s):
Jessica E Bourne, Sarah Sauchelli, Rachel Perry, Angie Page, Sam Leary, Clare England, Ashley R Cooper
Article Affiliation:
Jessica E Bourne
Abstract:
BACKGROUND: Electrically assisted bicycles (e-bikes) have been highlighted as a method of active travel that could overcome some of the commonly reported barriers to cycle commuting. The objective of this systematic review was to assess the health benefits associated with e-cycling.
METHOD: A systematic literature review of studies examining physical activity, cardiorespiratory, metabolic and psychological outcomes associated with e-cycling. Where possible these outcomes were compared to those from conventional cycling and walking. Seven electronic databases, clinical trial registers, grey literature and reference lists were searched up to November 2017. Hand searching occurred until June 2018. Experimental or observational studies examining the impact of e-cycling on physical activity and/or health outcomes of interest were included. E-bikes used must have pedals and require pedalling for electric assistance to be provided.
RESULTS: Seventeen studies (11 acute experiments, 6 longitudinal interventions) were identified involving a total of 300 participants. There was moderate evidence that e-cycling provided physical activity of at least moderate intensity, which was lower than the intensity elicited during conventional cycling, but higher than that during walking. There was also moderate evidence that e-cycling can improve cardiorespiratory fitness in physically inactive individuals. Evidence of the impact of e-cycling on metabolic and psychological health outcomes was inconclusive. Longitudinal evidence was compromised by weak study design and quality.
CONCLUSION: E-cycling can contribute to meeting physical activity recommendations and increasing physical fitness. As such, e-bikes offer a potential alternative to conventional cycling. Future research should examine the long-term health impacts of e-cycling using rigorous research designs.
Article Published Date : Jan 20, 2018
Abstract Title:
Associations Between Changes in Cycling and All-Cause Mortality Risk.
Abstract Source:
Am J Prev Med. 2018 11 ;55(5):615-623. PMID: 30342627
Abstract Author(s):
Lars Østergaard, Majken K Jensen, Kim Overvad, Anne Tjønneland, Anders Grøntved
Article Affiliation:
Lars Østergaard
Abstract:
INTRODUCTION: Previous cohort studies have reported relationships of active commuting, walking, and cycling with mortality. No studies have separately examined commuter and recreational cycling and how changes in cycling are related to mortality.
METHODS: Prospective cohort study among individuals who were between 50 and 65years and living in Denmark at the baseline examination between 1993 and 1997. Commuter/recreational cycling and changes in cycling were investigated in analytic samples of 28,204 and 15,272 participants, respectively. Participants were asked to provide information on cycling habits and other risk factors for mortality at baseline and 5years later and were followed for risk of death until July 2013. Data were analyzed in 2018.
RESULTS: Cycling between 1 and 60 minutes per week was associated with lower risk of all-cause mortality, with an appertaining multivariable adjusted hazard ratio of 0.76 (95% CI=0.69, 0.83) for recreational cycling and 0.78 (95% CI=0.63, 0.96) for commuter cycling when compared with no cycling. Compared with those who never cycled, the hazard ratio for those who initiated cycling was 0.78 (95% CI=0.67, 0.90) and the hazard ratio for those who consistently cycled was 0.77 (95% CI=0.71, 0.84), whereas the hazard ratio for those who stopped cycling was 0.98 (95% CI=0.87, 1.11).
CONCLUSIONS: Initiation of, or continued engagement in, cycling late in mid-life is associated with a lower risk of all-cause mortality. It may be suggested that national and local governments prioritize resources to promote cycling.
Article Published Date : Jan 10, 2018
Abstract Title:
Effect of E-Bike Versus Bike Commuting on Cardiorespiratory Fitness in Overweight Adults: A 4-Week Randomized Pilot Study.
Abstract Source:
Clin J Sport Med. 2018 05 ;28(3):255-265. PMID: 29095201
Abstract Author(s):
Christoph Höchsmann, Steffen Meister, Damiana Gehrig, Elisa Gordon, Yanlei Li, Monique Nussbaumer, Anja Rossmeissl, Juliane Schäfer, Henner Hanssen, Arno Schmidt-Trucksäss
Article Affiliation:
Christoph Höchsmann
Abstract:
OBJECTIVE: To assess if active commuting with an electrically assisted bicycle (e-bike) during a 4-week period can induce increases in cardiorespiratory fitness measured as peak oxygen uptake (V[Combining Dot Above]O2peak) in untrained, overweight individuals, and if these changes are comparable with those induced by a conventional bicycle.
DESIGN: Four-week randomized pilot study.
SETTING: Controlled laboratory.
PARTICIPANTS: Thirty-two volunteers (28 men) participated. Seventeen {median age 37 years [interquartile range (IQR) 34, 45], median body mass index [BMI] 29 kg/m [IQR 27, 31]} were randomized to the E-Bike group and 15 [median age 43 years (IQR 38, 45), median BMI 28 kg/m (IQR 26, 29)] to the Bike group.
INTERVENTIONS: Participants in both groups were instructed to use the bicycle allocated to them (e-bike or conventional bicycle) for an active commute to work in the Basel (Switzerland) area at a self-chosen speed on at least 3 days per week during the 4-week intervention period.
MAIN OUTCOME MEASURES: V[Combining Dot Above]O2peak was assessed before and after the intervention in an all-out exercise test on a bicycle ergometer.
RESULTS: V[Combining Dot Above]O2peak increased by an average of 3.6 mL/(kg·min) [SD 3.6 mL/(kg·min)] in the E-Bike group and by 2.2 mL/(kg·min) [SD 3.5 mL/(kg·min)] in the Bike group, with an adjusted difference between the 2 groups of 1.4 mL/(kg·min) [95% confidence interval, -1.4-4.1; P = 0.327].
CONCLUSIONS: E-bikes may have the potential to improve cardiorespiratory fitness similar to conventional bicycles despite the available power assist, as they enable higher biking speeds and greater elevation gain.
Article Published Date : Dec 31, 2017
Abstract Title:
Why Do You Ride?: A Characterization of Mountain Bikers, Their Engagement Methods, and Perceived Links to Mental Health and Well-Being.
Abstract Source:
Front Psychol. 2018 ;9:1642. Epub 2018 Sep 19. PMID: 30283372
Abstract Author(s):
Lisa Roberts, Gareth Jones, Rob Brooks
Article Affiliation:
Lisa Roberts
Abstract:
Mountain biking is an increasingly popular outdoor activity on the extreme sport continuum. Extreme and high-risk sports have been investigated using a variety of motivational theories with sensation seeking a dominant theme; however, behavioral and motivational homogeneity within these types of populations should not be assumed. Recent studies have highlighted the therapeutic potential of extreme sports and similar outdoor activities. The aim of this study was to describe the characteristics of mountain biking participants, their engagement methods, and perceived benefits to mental health and well-being. This was a cross-sectional survey and participants were recruited via social media. An online questionnaire specific to the domain of mountain biking was developed. Analysis of the full sample (= 1,484) and of three independent paired sub-samples was conducted using SPSS. The sub-samples compared the results of males and females; younger and older riders; and those who have recently engaged in downhill mountain biking and those who have not. The results have succeeded in identifying some disparities in mountain biker characteristics and engagement methods. The results suggest that some riders found pleasure in higher risk engagement. The study proposes various explanations for the disproportion of women in mountain biking. Irrespective of the confounding factors related to rider characteristics or engagement methods, mountain bikers reported copious benefits to mental health and well-being related to their engagement. There was a high reported usage of mountain biking as a coping strategy. As such, this study provides insights that could inform the development of outdoor activities as interventions for mental health.
Article Published Date : Dec 31, 2017
Abstract Title:
A Single Bout of Aerobic Exercise Improves Motor Skill Consolidation in Parkinson's Disease.
Abstract Source:
Front Aging Neurosci. 2018 ;10:328. Epub 2018 Oct 22. PMID: 30405397
Abstract Author(s):
Simon Steib, Philipp Wanner, Werner Adler, Jürgen Winkler, Jochen Klucken, Klaus Pfeifer
Article Affiliation:
Simon Steib
Abstract:
Motor learning is impaired in Parkinson's disease (PD), with patients demonstrating deficits in skill acquisition (online learning) and consolidation (offline learning) compared to healthy adults of similar age. Recent studies in young adults suggest that single bouts of aerobic exercise (AEX), performed in close temporal proximity to practicing a new motor task, may facilitate motor skill learning. Thus, we aimed at investigating the effects of a single bout of aerobic cycling on online and offline learning in PD patients.17 PD patients (Hoehn and Yahr 1 - 2.5, age: 64.4± 6.2) participated in this crossover study. Immediately prior to practicing a novel balance task, patients either performed 30 min of (i) moderate intensity (60-70% VO) aerobic cycling, or (ii) seated rest (order counterbalanced). The task required patients to stabilize a balance platform (stabilometer) in a horizontal position for 30 s. For each experimental condition, patients performed 15 acquisition trials, followed by a retention test 24 h later. We calculated time in balance (platform within± 5° from horizontal) for each trial, and analyzed within- and between-subjects differences in skill acquisition (online learning) and skill retention (offline learning) using mixed repeated-measures ANOVA.We found that the exercise bout had no effect on performance level or online gains during acquisition, despite affecting the time course of skill improvements (larger initial and reduced late skill gains). Aerobic cycling significantly improved offline learning, as reflected by larger 24-h skill retention compared to the rest condition.Our results suggest that a single bout of moderate-intensity AEX is effective in improving motor skill consolidation in PD patients. Thus, acute exercise may represent an effective strategy to enhance motor memory formation in this population. More work is necessary to understand the underlying mechanisms, the optimal scheduling of exercise, and the applicability to other motor tasks. Further, the potential for patients in later disease stages need to be investigated. The study was a priori registered at ClinicalTrials.gov (NCT03245216).
Article Published Date : Dec 31, 2017
Abstract Title:
Associations Between Bicycling for Transportation and Cardiometabolic Risk Factors Among Minneapolis-Saint Paul Area Commuters: A Cross-Sectional Study in Working-Age Adults.
Abstract Source:
Am J Health Promot. 2018 03 ;32(3):631-637. Epub 2017 Jun 1. PMID: 28569115
Abstract Author(s):
Aaron T Berger, Xinyi Lisa Qian, Mark A Pereira
Article Affiliation:
Aaron T Berger
Abstract:
PURPOSE: This study describes the association between frequency of bicycling for active transportation and modifiable cardiometabolic risk factors in the Minneapolis-Saint Paul (MSP) metropolitan area.
DESIGN: We conducted an online survey from a convenience sample of likely bicycle commuters.
SETTING: Participants were e-mailed invitations including a link to the online survey.
PARTICIPANTS: Participants (n = 1450, 15.6% response rate) were residents of the 7-county MSP metropolitan area aged 20 to 64 years.
MEASURES: Participants reported frequency of commute and destination cycling from April to September and October to March, prevalent cardiometabolic risk factors, and demographic covariates.
ANALYSIS: We performed logistic regressions for associations between average weekly transportation bicycling and self-reported prevalent obesity, high blood pressure, high cholesterol, low high-density lipoprotein cholesterol, and high triglycerides. We used Poisson regression for the count of cardiometabolic risk factors. All models were adjusted for age, sex, race, smoking, alcohol consumption, and other physical activity, with random intercepts by zip code.
RESULTS: Self-reported bicycling frequency is associated with significantly lower odds of prevalent obesity, hypertension, and high triglycerides. Three bicycling trips per week is associated with 20% fewer (95% confidence interval: 12%-28%) cardiometabolic risk factors.
CONCLUSION: Bicycling frequency is inversely associated with cardiometabolic risk factors. These results provide empirical support for the promotion of active transportation as public health policy.
Article Published Date : Dec 31, 2017
Abstract Title:
Metabolic recovery from heavy exertion following banana compared to sugar beverage or water only ingestion: A randomized, crossover trial.
Abstract Source:
PLoS One. 2018 ;13(3):e0194843. Epub 2018 Mar 22. PMID: 29566095
Abstract Author(s):
David C Nieman, Nicholas D Gillitt, Wei Sha, Debora Esposito, Sivapriya Ramamoorthy
Article Affiliation:
David C Nieman
Abstract:
OBJECTIVES AND METHODS: Using a randomized, crossover, counterbalanced approach, cyclists (N = 20, overnight fasted state) engaged in the four 75-km time trials (2-week washout) while ingesting two types of bananas with similar carbohydrate (CHO) but different phenolic content (Cavendish, CAV; mini-yellow, MIY, 63% higher polyphenols), a 6% sugar beverage (SUG), and water only (WAT). CHO intake was set at 0.2 g/kg every 15 minutes. Blood samples were collected pre-exercise and 0 h-, 0.75 h-,1.5 h-, 3 h-, 4.5 h-, 21 h-, 45 h-post-exercise.
RESULTS: Each of the CHO trials (CAV, MIY, SUG) compared to water was associated with higher post-exercise plasma glucose and fructose, and lower leukocyte counts, plasma 9+13 HODES, and IL-6, IL-10, and IL-1ra. OPLS-DA analysis showed that metabolic perturbation (N = 1,605 metabolites) for WAT (86.8±4.0 arbitrary units) was significantly greater and sustained than for CAV (70.4±3.9, P = 0.006), MIY (68.3±4.0, P = 0.002), and SUG (68.1±4.2, P = 0.002). VIP ranking (<3.0, N = 25 metabolites) showed that both CAV and MIY were associated with significant fold changes in metabolites including those from amino acid and xenobiotics pathways. OPLS-DA analysis of immediate post-exercise metabolite shifts showed a significant separation of CAV and MIY from both WAT and SUG (R2Y = 0.848, Q2Y = 0.409). COX-2 mRNA expression was lower in both CAV and MIY, but not SUG, versus WAT at 21-h post-exercise in THP-1 monocytes cultured in plasma samples. Analysis of immediate post-exercise samples showed a decrease in LPS-stimulated THP-1 monocyte extracellular acidification rate (ECAR) in CAV and MIY, but not SUG, compared to WAT.
CONCLUSIONS: CHO ingestion from bananas or a sugar beverage had a comparable influence in attenuating metabolic perturbation and inflammation following 75-km cycling. Ex-vivo analysis with THP-1 monocytes supported a decrease in COX-2 mRNA expression and reduced reliance on glycolysis for ATP production following ingestion of bananas but not sugar water when compared to water alone.
TRIAL REGISTRATION: ClinicalTrials.gov, U.S. National Institutes of Health, identifier: NCT02994628.
Article Published Date : Dec 31, 2017
Abstract Title:
Changes in Cycling and Incidence of Overweight and Obesity among Danish Men and Women.
Abstract Source:
Med Sci Sports Exerc. 2018 07 ;50(7):1413-1421. PMID: 29443821
Abstract Author(s):
Martin Gillies Rasmussen, Kim Overvad, Anne Tjønneland, Majken K Jensen, Lars Østergaard, Anders Grøntved
Article Affiliation:
Martin Gillies Rasmussen
Abstract:
PURPOSE: Overweight and obesity are associated with increased risk of several noncommunicable diseases and are a growing public health issue. The primary purpose of the current study was to investigate incidence of overweight and obesity according to 5-yr cycling habits. The secondary purpose was to investigate incidence of remission from overweight and obesity according to 5-yr cycling habits.
METHODS: We analyzed 9014 men and 8661 women without chronic disease who between 1993 and 2003 completed two assessments approximately 5 yr apart. At both assessments, participants reported habitual cycling habits. Also, body weight and waist circumference were measured by a laboratory technician at baseline and self-assessed at second examination. We computed multivariable adjusted odds ratios (OR) with 95% confidence intervals (CI) for development of and remission from abdominal and general overweight and obesity, according to 5-yr cycling habits.
RESULTS: Continued cycling was associated with lower odds for incidence of abdominal (men,>102 cm; women,>88 cm) and incidence of general (body mass index≥30 kg·m) obesity; compared with no cycling, OR (95% CI) values were 0.82 (0.74-0.91) and 0.74 (0.60-0.92) for abdominal and general obesity, respectively. Also, those who initiated cycling had lower odds for incidence of abdominal obesity; OR (95% CI) was 0.85 (0.73-1.00) relative to no cycling.Although we found no evidence of remission from abdominal and general overweight and obesity according to 5-yr cycling habits, those who continued cycling had significantly larger decreases in waist circumference relative to noncyclists (β coefficient (95% CI), -0.95 cm (-1.56 to -0.33 cm)).
CONCLUSIONS: Continued cycling compared with no cycling was associated with lower odds for abdominal and general obesity. Also, late-in-life initiation of cycling was associated with lower odds for abdominal obesity relative to no cycling.
Article Published Date : Dec 31, 2017
Abstract Title:
The effect of dietary nitrate supplementation on the spatial heterogeneity of quadriceps deoxygenation during heavy-intensity cycling.
Abstract Source:
Physiol Rep. 2017 Jul ;5(14). PMID: 28743821
Abstract Author(s):
Brynmor C Breese, David C Poole, Dai Okushima, Stephen J Bailey, Andrew M Jones, Narihiko Kondo, Tatsuro Amano, Shunsaku Koga
Article Affiliation:
Brynmor C Breese
Abstract:
This study investigated the influence of dietary inorganic nitrate (NO) supplementation on pulmonary Ouptake (V˙O) and muscle deoxyhemoglobin/myoglobin (i.e. deoxy [Hb + Mb]) kinetics during submaximal cycling exercise. In a randomized, placebo-controlled, cross-over study, eight healthy and physically active male subjects completed two step cycle tests at a work rate equivalent to 50% of the difference between the gas exchange threshold and peak V˙Oover separate 4-day supplementation periods with NO-rich (BR; providing 8.4 mmol NO∙day) and NO-depleted (placebo; PLA) beetroot juice. Pulmonary V˙Owas measured breath-by-breath and time-resolved near-infrared spectroscopy was utilized to quantify absolute deoxy [Hb + Mb] and total [Hb + Mb] within the,, andThere were no significant differences (>0.05) in the primary deoxy [Hb + Mb] mean response time or amplitude between the PLA and BR trials at each muscle site. BR significantly increased the mean (three-site) end-exercise deoxy [Hb + Mb] (PLA: 91 ± 9 vs. BR: 95 ± 12 mol/L,<0.05), with a tendency to increase the mean (three-site) area under the curve for total [Hb + Mb] responses (PLA: 3650 ± 1188 vs. BR: 4467 ± 1315 mol/L sec,=0.08). The V˙Oslow component reduction after BR supplementation (PLA: 0.27 ± 0.07 vs. BR: 0.23 ± 0.08 L min,=0.07) correlated inversely with the mean increases in deoxy [Hb + Mb] and total [Hb + Mb] across the three muscle regions ( = 0.62 and 0.66,<0.05). Dietary NOsupplementation increased Odiffusive conductance across locomotor muscles in association with improved V˙Odynamics during heavy-intensity cycling transitions.
Article Published Date : Jun 30, 2017
Abstract Title:
Effect of New Zealand Blackcurrant Extract on Repeated Cycling Time Trial Performance.
Abstract Source:
Sports (Basel). 2017 May 9 ;5(2). Epub 2017 May 9. PMID: 29910385
Abstract Author(s):
Connor A Murphy, Matthew D Cook, Mark E T Willems
Article Affiliation:
Connor A Murphy
Abstract:
New Zealand blackcurrant (NZBC) extract increased 16.1 km cycling time trial performance. The aim of the present study was to examine the effect of NZBC extract on 2× 4 km time trial performance. Ten male cyclists (age: 30 ± 12 years, body mass: 74 ± 9 kg, height: 179 ± 7 cm, body fat: 11 ± 3%, (V̇) ̇O2max: 55 ± 7 mL•kg-1•min-1, mean ± SD) volunteered. Participants were familiarized with the time trials. Participants consumed capsulated NZBC extract (300 mg∙day-1 CurraNZ™; containing 105 mg anthocyanin) or placebo for seven days (double blind, randomised, cross-over design, wash-out at least seven days) before 2 × 4 km time trials (10 min active self-paced recovery between trials) (SRM ergometer, SRM International, Germany). Heart rate was recorded and blood lactate sampled immediately after each trial and 8 min into recovery between the trials. Times over comparable one km distances in each 4 km time trial were similar. No effect was observed for the time to complete the first (placebo: 380 ± 28 s, NZBC: 377 ± 27 s) and second 4km of cycling (placebo: 391 ± 32 s, NZBC: 387 ± 30 s), within both groups the second 4 km times slower by 11 ± 8 s and 11 ± 9 s for placebo and NZBC, respectively. However, the total time of the two 4 km cycling trials was 0.82% faster with NZBC extract (placebo: 771 ± 60 s, NZBC 764 ± 56 s,p = 0.034) with seven participants having faster total times. There was no effect of NZBC on heart rate and lactate values at identical time points. New Zealand blackcurrant extract seems to be beneficial in repeated short-distance cycling time trials for overall performance.
Article Published Date : May 08, 2017
Abstract Title:
Bicycling for transportation improves heart rate variability in young adults.
Abstract Source:
J Sports Med Phys Fitness. 2017 Mar ;57(3):299-304. Epub 2015 Dec 18. PMID: 26684436
Abstract Author(s):
Henrique M Bueno, Michelle Sartori, Hidalina R Macedo, Ivana C Moraes-Silva, Federico Aletti, Maria C Irigoyen, Kátia DE Angelis
Article Affiliation:
Henrique M Bueno
Abstract:
BACKGROUND: Physical activity has been considered an effective method to treat and prevent cardiovascular and metabolic disease. An important mechanism benefited by exercise training is the cardiovascular autonomic control, often impaired in cardiometabolic disease. Cycling used as a daily means of transport can be considered an interesting alternative to regular physical exercise practice. Therefore, this study intent to compare metabolic, hemodynamic and cardiovascular autonomic profiles of young adult men who were used to cycle for transportation (CT) with those considered insufficiently actives (IA).
METHODS: Body composition, blood pressure, glucose, total cholesterol and triglycerides were evaluated at rest. Heart rate variability was analyzed in time and frequency domains.
RESULTS: No differences were observed for body composition, blood pressure, glycemia nor lipids between groups. CT group presented resting bradycardia. Heart rate variability was increased in cyclists, as well as the parameters of parasympathetic modulation. Sympathetic modulation was reduced in CT group when compared to IA group. Additionally, positive correlations were observed between resting heart rate and RMSSD and heart rate variability, while heart rate variability was correlated with sympathovagal balance.
CONCLUSIONS: Our results demonstrated that bicycling regularly used as a means of transport is able to improve cardiovascular autonomic modulation, thus reducing the risk of cardiovascular disease.
Article Published Date : Feb 28, 2017
Abstract Title:
Improved cognition while cycling in Parkinson's disease patients and healthy adults.
Abstract Source:
Brain Cogn. 2017 04 ;113:23-31. Epub 2017 Jan 11. PMID: 28088064
Abstract Author(s):
Audrey A Hazamy, Lori J P Altmann, Elizabeth Stegemöller, Dawn Bowers, Hyo Keun Lee, Jonathan Wilson, Michael S Okun, Chris J Hass
Article Affiliation:
Audrey A Hazamy
Abstract:
Persons with Parkinson's disease (PD) are typically more susceptible than healthy adults to impaired performance when two tasks (dual task interference) are performed simultaneously. This limitation has by many experts been attributed to limitations in cognitive resources. Nearly all studies of dual task performance in PD employ walking or balance-based motor tasks, which are commonly impaired in PD. These tasks can be performed using a combination of one or two executive function tasks. The current study examined whether persons with PD would demonstrate greater dual task effects (DTEs) on cognition compared to healthy older adults (HOAs) during a concurrent cycling task. Participants with and without PD completed a battery of 12 cognitive tasks assessing visual and verbal processing in the following cognitive domains: speed of processing, controlled processing, working memory and executive function. Persons with PD exhibited impairments compared to healthy participants in select tasks (i.e., 0-back, 2-back and operation span). Further, both groups unexpectedly exhibited dual task facilitation of response times in visual tasks across cognitive domains, and improved verbal recall during an executive function task. Only one measure, 2-back, showed a speed-accuracy trade-off in the dual task. These results demonstrate that, when paired with a motor task in which they are not impaired, people with PD exhibit similar DTEs on cognitive tasks as HOAs, even when these task effects are facilitative. More generally, these findings demonstrate that pairing cognitive tasks with cycling may actually improve cognitive performance which may have therapeutic relevance to cognitive decline associated with aging and PD pathology.
Article Published Date : Dec 31, 2016
Abstract Title:
Cycling to School and Body Composition, Physical Fitness, and Metabolic Syndrome in Children and Adolescents.
Abstract Source:
J Pediatr. 2017 09 ;188:57-63. Epub 2017 Jun 23. PMID: 28651798
Abstract Author(s):
Robinson Ramírez-Vélez, Antonio García-Hermoso, Cesar Agostinis-Sobrinho, Jorge Mota, Rute Santos, Jorge Enrique Correa-Bautista, Deisy Constanza Amaya-Tambo, Emilio Villa-González
Article Affiliation:
Robinson Ramírez-Vélez
Abstract:
OBJECTIVE: To evaluate the association between cycling to/from school and body composition, physical fitness, and metabolic syndrome among a sample of Colombian children and adolescents.
STUDY DESIGN: During the 2014-2015 school year, we examined a cross-sectional component of the Association for muscular strength with early manifestation of cardiovascular disease risk factors among Colombian children and adolescents (FUPRECOL) study. Participants included 2877 youths (54.5% girls) from Bogota, Colombia. A self-reported questionnaire was used to measure the frequency and mode of commuting to school. Four components of physical fitness were measured: (1) anthropometric (height, weight, body mass index, and waist circumference); (2) musculoskeletal (handgrip and standing long jump test); (3) motor (speed-agility test; 4 × 10-meter shuttle run); and (4) cardiorespiratory (20-m shuttle run test [20mSRT]). The prevalence of metabolic syndrome was determined by the definitions provided by the International Diabetes Federation.
RESULTS: Twenty-three percent of the sample reported commuting by cycle. Active commuting boys had a likelihood of having an unhealthy 4 × 10 m value (OR, 0.72; 95% CI, 0.53-0.98; P = .038) compared with the reference group (passive commuters). Active commuting girls showed a lower likelihood of having unhealthy a 20mSRT value (OR, 0.81; 95% CI, 0.56-0.99; P = .047) and metabolic syndrome (OR, 0.61; 95% CI, 0.35-0.99; P = .048) compared with passive commuters.
CONCLUSION: Regular cycling to school may to be associated with better physical fitness and a lower incidence of metabolic syndrome than passive transport, especially in girls.
Article Published Date : Dec 31, 2016
Abstract Title:
Long-term bicycle riding ameliorates the depression of the patients undergoing hemodialysis by affecting the levels of interleukin-6 and interleukin-18.
Abstract Source:
Neuropsychiatr Dis Treat. 2017 ;13:91-100. Epub 2016 Dec 28. PMID: 28096677
Abstract Author(s):
Chunhui Zhao, Hui Ma, Lei Yang, Yong Xiao
Article Affiliation:
Chunhui Zhao
Abstract:
PURPOSE: Hemodialysis patients with depression have a higher risk of death and hospitalization. Although there is pharmacological management for the depression of hemodialysis patients, the adverse effect of the drug limits the use. The nonpharmacological way, bicycle riding, may be an effective way for the therapy of the depression in hemodialysis patients. However, the underlying mechanism of this relationship is still not fully explained, while interleukin-6 (IL-6) and interleukin-18 (IL-18) are associated with depression and exercise. Thus, the effects of bicycle riding on the levels of the interleukin were explored.
PARTICIPANTS AND METHODS: One hundred and eighty-nine patients with chronic hemodialysis were selected and randomly assigned to three groups of medicine (MG, received 20-mg escitalopram daily), medicine and aerobic exercise (MAG, received 20-mg escitalopram daily and bicycle riding six times weekly), and only aerobic exercise (AG, received 20-mg placebo daily and bicycle riding six times weekly). The whole experiment lasted for 18 weeks. The quality of life (36-Item Short Form Health Survey) and depression severity according to criteria in the Diagnostic and Statistical Manual of Mental Disorders, fourth edition [DSM-IV] were measured before and at the end of this study. The serum levels of IL-6 and IL-18 were measured by an enzyme-linked immunosorbent assay kit.
RESULTS: The quality of life was improved and depression severity was reduced significantly in the MAG and AG groups when compared with the MG group (P<0.05). Serum levels of IL-6 and IL-18 were the highest in the MG group, moderate in the MAG group and the lowest in AG group. On the other hand, the serum levels of IL-6 and IL-18 were closely associated with depression scores (P<0.05).
CONCLUSION: Aerobic exercise improves the quality of life and ameliorates the depression severity of the patients undergoing hemodialysis by affecting the levels of IL-6 and IL-18. Bicycle riding is a potential way for the depression therapy of the patients with chronic hemodialysis.
Article Published Date : Dec 31, 2016
Abstract Title:
Whole Body Vibration Increases Subsequent Sprint Performance in Well-Trained Cyclists.
Abstract Source:
Int J Sports Physiol Perform. 2016 Dec 14:1-18. Epub 2016 Dec 14. PMID: 27967282
Abstract Author(s):
Bent R Rønnestad, Gunnar Slettaløkken Falch, Stian Ellefsen
Article Affiliation:
Bent R Rønnestad
Abstract:
PURPOSE: Postactivation potentiation (PAP) exercise with added whole-body vibration (WBV) has been suggested as a potential way to acutely improve sprint performance. In cycling, there are many competitions and situations where sprinting abilities are important. In the present study we investigated the effect of adding WBV to warm-up procedures on subsequent cycle sprint performance.
METHODS: Eleven well-trained cyclists participated in the study. All cyclists performed a familiarization session before two separate test sessions in randomized order. Each session included a standardized warm-up followed by one of the following preconditioning exercises; 30 s of half-squats without WBV or 30 s of half-squats with WBV at 40 Hz. A 15 s Wingate sprint was performed one minute after the preconditioning exercise.
RESULTS: Performing preconditioning exercise with WBV at 40 Hz resulted in superior peak power output compared to preconditioning exercise without WBV (1413±257 W vs. 1353±213 W, p=0.04) and a tendency towards superior mean power output during a 15 s all-out sprint (850±119 W vs. 828±101 W, p=0.08). Effect sizes showed a moderate practical effect of WBV vs. no WBV on both peak and mean power output.
CONCLUSIONS: In conclusion, preconditioning exercise performed with WBV at 40 Hz seems to have a positive effect on cycling sprint performance in young well-trained cyclists. This suggests that athletes can incorporate body-loaded squats with WBV into preparations to specific sprint training to improve the quality of the sprint training and also in order to improve sprint performance in relevant competitions.
Article Published Date : Dec 13, 2016
Abstract Title:
A randomized controlled trial examining the effects of 16 weeks of moderate-to-intensive cycling and honey supplementation on lymphocyte oxidative DNA damage and cytokine changes in male road cyclists.
Abstract Source:
Cytokine. 2016 Sep 24 ;88:222-231. Epub 2016 Sep 24. PMID: 27676156
Abstract Author(s):
Behzad Hajizadeh Maleki, Bakhtyar Tartibian, Frank C Mooren, Karsten Krüger, Leah Z FitzGerald, Mohammad Chehrazi
Article Affiliation:
Behzad Hajizadeh Maleki
Abstract:
The aim of this study was to investigate whether honey supplementation (70g, ninety minutes before each training session) attenuates changes in lymphocyte counts, DNA damage, cytokines, antioxidative and peroxidative biomarkers following moderate-to-intensive exercise training in male road cyclists. Healthy nonprofessional cyclists (n=24, aged 17-26years) were randomly assigned to exercise+supplement (EX+S, n=12) and exercise (EX, n=12) groups for an experimental period of 16weeks. Moderate-to-intensive exercise training increased lymphocytes DNA damage, cytokines and peroxidative biomarkers as well as decreased antioxidative biomarkers in the EX group. These changes were significantly attenuated in the EX+S group. Furthermore, for both groups the observed changes in peroxidative and antioxidative biomarkers could be correlated positively and negatively, respectively, with lymphocyte DNA damage and cytokines. Findings suggest that honey attenuates oxidative stress and lymphocyte DNA damage after exercise, activities that are most likely attributable to its high antioxidant capacity.
Article Published Date : Sep 23, 2016
Abstract Title:
Daily consumption of tea catechins improves aerobic capacity in healthy male adults: a randomized double-blind, placebo-controlled, crossover trial.
Abstract Source:
Biosci Biotechnol Biochem. 2016 Aug 26:1-6. Epub 2016 Aug 26. PMID: 27562352
Abstract Author(s):
Noriyasu Ota, Satoko Soga, Akira Shimotoyodome
Article Affiliation:
Noriyasu Ota
Abstract:
Our previous studies demonstrated that dietary supplementation with tea catechins combined with exercise improved endurance capacity in mice. This study aimed to demonstrate the effect of daily tea catechin consumption on aerobic capacity in humans. Sixteen Japanese non-athlete male subjects (aged 25-47 years) took 500 mL of a test beverage with or without tea catechins (570 mg) daily for 8 weeks and attended a training program twice a week. Aerobic capacity was evaluated by indirect calorimetry and near-infrared spectroscopy during graded cycle exercise. Catechin beverage consumption was associated with a significantly higher ventilation threshold during exercise and a higher recovery rate of oxygenated hemoglobin and myoglobin levels after graded cycle exercise when compared to subjects receiving the placebo beverage. These results indicate that daily consumption of tea catechins increases aerobic capacity when combined with semiweekly light exercise, which may be due to increased skeletal muscle aerobic capacity.
Article Published Date : Aug 25, 2016
Abstract Title:
High-Speed Cycling Intervention Improves Rate-Dependent Mobility in Older Adults.
Abstract Source:
Med Sci Sports Exerc. 2016 Aug 6. Epub 2016 Aug 6. PMID: 27501360
Abstract Author(s):
Maria Bellumori, Mehmet Uygur, Christopher A Knight
Article Affiliation:
Maria Bellumori
Abstract:
PURPOSE: The aim was to determine the feasibility of a six-week speed-based exercise program that could be used to initiate new exercise behaviors and improve rapid movement in older adults approaching frailty.
METHODS: The intervention group included 14 older adults (3 males, 11 females, mean (SD) age: 70 (7.6) years, height: 1.6 (.11) m, mass: 76.8 (12.0) kg, BMI: 27.7(4.7)). The control group included 12 older adults (6 males, 6 females, mean (SD) age: 69.2 (6.9) years, height: 1.7 (.09) m, mass: 78.2 (10.9) kg, BMI: 25.3 (2.7)). Subjects included active older adults, including regular exercisers, but none were engaged in sports or exercises with an emphasis on speed (e.g. cycling spin classes or tennis). Stationary recumbent cycling was selected to minimize fall risk and low pedaling resistance reduced musculoskeletal and cardiovascular load. Two weekly 30-minute exercise sessions consisted of interval training in which subjects pedaled at preferred cadence and performed ten 20-s fast cadence intervals separated by 40-s of active recovery at preferred cadence.
RESULTS: Significant Group by Time interactions (p<.05) supported a 2-s improvement in the timed up and go test and a 34% improvement in rapid isometric knee extension contractions in the exercise group but not in controls. Central neural adaptations are suggested because this lower extremity exercise program also elicited significant improvements in the untrained upper extremities of the exercise group (elbow extension RFD-SF and 9-Hole Peg Test, p<.05).
CONCLUSION: These results demonstrate that a relatively low dose of speed-based exercise can improve neuromuscular function and tests of mobility in older adults. Such a program serves as a sensible precursor to subsequent, more vigorous training or as an adjunct to a program where a velocity emphasis is lacking.
Article Published Date : Aug 05, 2016
Abstract Title:
Associations between Recreational and Commuter Cycling, Changes in Cycling, and Type 2 Diabetes Risk: A Cohort Study of Danish Men and Women.
Abstract Source:
PLoS Med. 2016 07 ;13(7):e1002076. Epub 2016 Jul 12. PMID: 27403867
Abstract Author(s):
Martin G Rasmussen, Anders Grøntved, Kim Blond, Kim Overvad, Anne Tjønneland, Majken K Jensen, Lars Østergaard
Article Affiliation:
Martin G Rasmussen
Abstract:
BACKGROUND: Cycling is a recreational activity and mode of commuting with substantial potential to improve public health in many countries around the world. The aim of this study was to examine prospective associations between recreational and commuter cycling, changes in cycling habits, and risk of type 2 diabetes (T2D) in Danish adults from the Diet, Cancer and Health cohort study.
METHODS AND FINDINGS: At baseline from 1993 to 1997, 24,623 men and 27,890 women from Denmark, 50-65 y of age and free of T2D and other chronic diseases, underwent a number of assessments, including completing a lifestyle questionnaire also addressing cycling habits. Approximately 5 y later, at a second examination, participants completed a new, updated lifestyle questionnaire. Cox regression was used to estimate hazard ratios (HRs) of incident T2D registered in the Danish National Diabetes Registry, according to recreational and commuter cycling and changes in cycling habits, with adjustment for a priori known T2D risk factors. During 743,245.4 person-years of follow-up (mean follow-up 14.2 y), 6,779 incident cases of T2D were documented. Multivariable adjusted HRs (95% confidence interval [CI]) were 1, 0.87 (0.82, 0.93), 0.83 (0.77, 0.89), 0.80 (0.74, 0.86) and 0.80 (0.74, 0.87) (p for trend =<0.001) for 0, 1-60, 61-150, 151-300, and>300 min/wk of total cycling (recreational and commuter cycling), respectively. In analysis of seasonal cycling, multivariable adjusted HRs (95% CI) were 1, 0.88 (0.83, 0.94), and 0.80 (0.76, 0.85) for non-cyclists, seasonal cyclists (those cycling only in summer or winter), and those cycling during both summer and winter, respectively. How changes in total cycling from baseline to the second examination affected risk was also investigated, and multivariable adjusted HRs (95% CI) were 1, 0.88 (0.78, 1.01), 0.80 (0.69, 0.91), and 0.71 (0.65, 0.77) for non-cyclists and for those who ceased, initiated, or continued cycling between baseline and the second examination, respectively. Lastly, in the analysis of commuter cycling, multivariable HRs (95% CI) were 1, 0.72 (0.60, 0.87), 0.83 (0.69, 1.00), and 0.70 (0.57, 0.85) (p for trend =<0.001) for cycling 0, 1-60, 61-150, and>150 min/wk to work, respectively. The main limitation of the current study is the use of self-reported physical activity.
CONCLUSIONS: Commuter and recreational cycling was consistently associated with lower risk of T2D in Danish adults. Our results also provide evidence that late-in-life initiation of or continued engagement in cycling lowers risk of T2D.
Article Published Date : Dec 31, 2015
Abstract Title:
New Zealand blackcurrant extract improves cycling performance and fat oxidation in cyclists.
Abstract Source:
Eur J Appl Physiol. 2015 Jul 15. Epub 2015 Jul 15. PMID: 26175097
Abstract Author(s):
Matthew David Cook, Stephen David Myers, Sam David Blacker, Mark Elisabeth Theodorus Willems
Article Affiliation:
Matthew David Cook
Abstract:
PURPOSE: Blackcurrant intake increases peripheral blood flow in humans, potentially by anthocyanin-induced vasodilation which may affect substrate delivery and exercise performance. We examined the effects of New Zealand blackcurrant (NZBC) extract on substrate oxidation, cycling time-trial performance and plasma lactate responses following the time-trial in trained cyclists.
METHODS: Using a randomized, double-blind, crossover design, 14 healthy men (age: 38 ± 13 years, height: 178 ± 4 cm, body mass: 77 ± 9 kg, [Formula: see text]O2max: 53 ± 6 mL kg(-1) min(-1), mean ± SD) ingested NZBC extract (300 mg day(-1) CurraNZ™ containing 105 mg anthocyanin) or placebo (PL, 300 mg microcrystalline cellulose M102) for 7 days (washout14 days). On day 7, participants performed 30 min of cycling (3 × 10 min at 45, 55 and 65 % [Formula: see text]O2max), followed by a 16.1 km time-trial with lactate sampling during a 20-min passive recovery.
RESULTS: NZBC extract increased fat oxidation at 65 % [Formula: see text]O2max by 27 % (P < 0.05) and improved 16.1 km time-trial performance by 2.4 % (NZBC: 1678 ± 108 s, PL: 1722 ± 131 s, P < 0.05). Plasma lactate was higher with NZBC extract immediately following the time-trial (NZBC: 7.06 ± 1.73 mmol L(-1), PL: 5.92 ± 1.58 mmol L(-1), P < 0.01).
CONCLUSIONS: Seven-day intake of New Zealand blackcurrant extract improves 16.1 km cycling time-trial performance and increases fat oxidation during moderate intensity cycling.
Article Published Date : Jul 14, 2015
Abstract Title:
Effect of sauna-based heat acclimation on plasma volume and heart rate variability.
Abstract Source:
Eur J Appl Physiol. 2015 Apr ;115(4):785-94. Epub 2014 Nov 29. PMID: 25432420
Abstract Author(s):
Jamie Stanley, Aaron Halliday, Shaun D'Auria, Martin Buchheit, Anthony S Leicht
Article Affiliation:
Jamie Stanley
Abstract:
PURPOSE: We investigated the effect of post-exercise sauna bathing on plasma volume (PV) expansion and whether such responses can be tracked by changes in heart rate (HR)-based measures.
METHODS: Seven, well-trained male cyclists were monitored for 35 consecutive days (17 days baseline training, 10 days training plus sauna, 8 days training). Sauna exposure consisted of 30 min (87°C, 11 % relative humidity) immediately following normal training. Capillary blood samples were collected while resting seated to assess PV changes. HR (HRwake) and vagal-related HR variability (natural logarithm of square root mean squared differences of successive R-R intervals, ln rMSSDwake) were assessed daily upon waking. A sub-maximal cycle test (5 min at 125 W) was performed on days 1, 8, 15, 22, 25, 29, and 35 and HR recovery (HRR60s) and ln rMSSDpostex were assessed post-exercise. Effects were examined using magnitude-based inferences.
RESULTS: Compared with baseline, sauna resulted in: (1) peak PV expansion after four exposures with a likely large increase [+17.8 % (90 % confidence limits, 7.4; 29.2)]; (2) reduction of HRwake by a trivial-to-moderate amount [-10.2 % (-15.9; -4.0)]; (3) trivial-to-small changes for ln rMSSDwake [4.3 % (1.9; 6.8)] and ln rMSSDpostex [-2.4 % (-9.1; 4.9)]; and (4) a likely moderate decrease in HRR60s [-15.6 % (-30.9; 3.0)]. Correlations between individual changes in PV and HR measures were all unclear.
CONCLUSIONS: Sauna bathing following normal training largely expanded PV in well-trained cyclists after just four exposures. The utility of HR and HRV indices for tracking changes in PV was uncertain. Future studies will clarify mechanisms and performance benefits of post-training sauna bathing.
Article Published Date : Mar 31, 2015
Abstract Title:
Dose-response associations between cycling activity and risk of hypertension in regular cyclists: The UK Cycling for Health Study.
Abstract Source:
J Hum Hypertens. 2015 Apr ;29(4):219-23. Epub 2014 Oct 2. PMID: 25273856
Abstract Author(s):
M Hollingworth, A Harper, M Hamer
Article Affiliation:
M Hollingworth
Abstract:
Most population studies on physical activity and health have involved largely inactive men and women, thus making it difficult to infer if health benefits occur at exercise levels above the current minimum guidelines. The aim was to examine associations between cycling volume and classical cardiovascular risk markers, including hypertension and hypercholesterolemia, in a population sample of habitual cyclists. A nationwide sample comprising 6949 men and women (aged 47.6 years on average) completed questions about their cycling levels, demographics and health. Nearly the entire sample (96.3%) achieved the current minimum physical activity recommendation through cycling alone. There was a dose-response association between cycling volume and risk of diagnosed hypertension (P-trend =0.001), with odds ratios of 0.98 (95% confidence interval (CI), 0.80-1.21), 0.86 (0.70, 1.06), 0.67 (95% CI, 0.53-0.83) across categories of 23-40, 40-61 and>61 metabolic equivalent hours/week (MET-h/week) compared with<23 MET-h/week. These associations persisted in models adjusted for age, sex, smoking, alcohol, body mass index (BMI) and other moderatevigorous physical activities. We also observed inverse associations between cycling volume and other risk factors including BMI and hypercholesterolemia. In summary, results from a population sample of cyclists suggest that additional cardiovascular health benefits can be achieved beyond the current minimum physical activity recommendation.
Article Published Date : Mar 31, 2015
Abstract Title:
Cycle training induces muscle hypertrophy and strength gain: strategies and mechanisms.
Abstract Source:
Acta Physiol Hung. 2015 Mar ;102(1):1-22. PMID: 25804386
Abstract Author(s):
Hayao Ozaki, J P Loenneke, R S Thiebaud, T Abe
Article Affiliation:
Hayao Ozaki
Abstract:
Cycle training is widely performed as a major part of any exercise program seeking to improve aerobic capacity and cardiovascular health. However, the effect of cycle training on muscle size and strength gain still requires further insight, even though it is known that professional cyclists display larger muscle size compared to controls. Therefore, the purpose of this review is to discuss the effects of cycle training on muscle size and strength of the lower extremity and the possible mechanisms for increasing muscle size with cycle training. It is plausible that cycle training requires a longer period to significantly increase muscle size compared to typical resistance training due to a much slower hypertrophy rate. Cycle training induces muscle hypertrophy similarly between young and older age groups, while strength gain seems to favor older adults, which suggests that the probability for improving in muscle quality appears to be higher in older adults compared to young adults. For young adults, higher-intensity intermittent cycling may be required to achieve strength gains. It also appears that muscle hypertrophy induced by cycle training results from the positive changes in muscle protein net balance.
Article Published Date : Feb 28, 2015
Abstract Title:
Improvement of 10-km time-trial cycling with motivational self-talk compared with neutral self-talk.
Abstract Source:
Int J Sports Physiol Perform. 2015 Mar ;10(2):166-71. Epub 2014 Jul 8. PMID: 25010539
Abstract Author(s):
Martin J Barwood, Jo Corbett, Christopher R D Wagstaff, Dan McVeigh, Richard C Thelwell
Article Affiliation:
Martin J Barwood
Abstract:
PURPOSE: Unpleasant physical sensations during maximal exercise may manifest themselves as negative cognitions that impair performance, alter pacing, and are linked to increased rating of perceived exertion (RPE). This study examined whether motivational self-talk (M-ST) could reduce RPE and change pacing strategy, thereby enhancing 10-km time-trial (TT) cycling performance in contrast to neutral self-talk (N-ST).
METHODS: Fourteen men undertook 4 TTs, TT1-TT4. After TT2, participants were matched into groups based on TT2 completion time and underwent M-ST (n=7) or N-ST (n=7) after TT3. Performance, power output, RPE, and oxygen uptake (VO2) were compared across 1-km segments using ANOVA. Confidence intervals (95%CI) were calculated for performance data.
RESULTS: After TT3 (ie, before intervention), completion times were not different between groups (M-ST, 1120±113 s; N-ST, 1150±110 s). After M-ST, TT4 completion time was faster (1078±96 s); the N-ST remained similar (1165±111 s). The M-ST group achieved this through a higher power output and VO2 in TT4 (6th-10th km). RPE was unchanged. CI data indicated the likely true performance effect lay between13- and 71-s improvement (TT4 vs TT3).
CONCLUSION: M-ST improved endurance performance and enabled a higher power output, whereas N-ST induced no change. The VO2 response matched the increase in power output, yet RPE was unchanged, thereby inferring a perceptual benefit through M-ST. The valence and content of self-talk are important determinants of the efficacy of this intervention. These findings are primarily discussed in the context of the psychobiological model of pacing.
Article Published Date : Feb 28, 2015
Abstract Title:
The Effects of Aerobic Exercise on Cognitive Function of Alzheimer's Disease Patients.
Abstract Source:
CNS Neurol Disord Drug Targets. 2015 ;14(10):1292-7. PMID: 26556080
Abstract Author(s):
Si-Yu Yang, Chun-Lei Shan, He Qing, Wei Wang, Yi Zhu, Meng-Mei Yin, Sergio Machado, Ti-Fei Yuan, Ting Wu
Article Affiliation:
Si-Yu Yang
Abstract:
To evaluate the effect of moderate intensity of aerobic exercise on elderly people with mild Alzheimer's disease, we recruited fifty volunteers aged 50 years to 80 years with cognitive impairment. They were randomized into two groups: aerobic group (n=25) or control group (n=25). The aerobic group was treated with cycling training at 70% of maximal intensity for 40 min/d, 3 d/wk for 3 months. The control group was only treated with heath education. Both groups were received cognitive evaluation, laboratory examination before and after 3 months. The results showed that the Minimum Mental State Examination score, Quality of Life Alzheimer's Disease score and the plasma Apo-a1 level was significantly increased (P<0.05), the Alzheimer's Disease Assessment Scale-cognition score, Neuropsychiatric Inventory Questionnaire score was significantly decreased.(P<0.05) in aerobic group before and after 3 months in aerobic group. For the control group, there was no significant difference in scores of Alzheimer's Disease Assessment Scale-cognition, Neuropsychiatric Inventory Questionnaire, Quality of Life Alzheimer's Disease, Apo-a1 (P>0.05), while Minimum Mental State Examination scores decreased significantly after 3 months (P<0.05). In conclusion, moderate intensity of aerobic exercise can improve cognitive function in patients with mild Alzheimer's disease.
Article Published Date : Dec 31, 2014
Abstract Title:
Unexpected dual task benefits on cycling in Parkinson disease and healthy adults: a neuro-behavioral model.
Abstract Source:
PLoS One. 2015 ;10(5):e0125470. Epub 2015 May 13. PMID: 25970607
Abstract Author(s):
Lori J P Altmann, Elizabeth Stegemöller, Audrey A Hazamy, Jonathan P Wilson, Michael S Okun, Nikolaus R McFarland, Aparna Wagle Shukla, Chris J Hass
Article Affiliation:
Lori J P Altmann
Abstract:
BACKGROUND: When performing two tasks at once, a dual task, performance on one or both tasks typically suffers. People with Parkinson's disease (PD) usually experience larger dual task decrements on motor tasks than healthy older adults (HOA). Our objective was to investigate the decrements in cycling caused by performing cognitive tasks with a range of difficulty in people with PD and HOAs.
METHODS: Twenty-eight participants with Parkinson's disease and 20 healthy older adults completed a baseline cycling task with no secondary tasks and then completed dual task cycling while performing 12 tasks from six cognitive domains representing a wide range of difficulty.
RESULTS: Cycling was faster during dual task conditions than at baseline, and was significantly faster for six tasks (all p<.02) across both groups. Cycling speed improved the most during the easiest cognitive tasks, and cognitive performance was largely unaffected. Cycling improvement was predicted by task difficulty (p<.001). People with Parkinson's disease cycled slower (p<.03) and showed reduced dual task benefits (p<.01) than healthy older adults.
CONCLUSIONS: Unexpectedly, participants' motor performance improved during cognitive dual tasks, which cannot be explained in current models of dual task performance. To account for these findings, we propose a model integrating dual task and acute exercise approaches which posits that cognitive arousal during dual tasks increases resources to facilitate motor and cognitive performance, which is subsequently modulated by motor and cognitive task difficulty. This model can explain both the improvement observed on dual tasks in the current study and more typical dual task findings in other studies.
Article Published Date : Dec 31, 2014
Abstract Title:
Health benefits of cycle ergometer training for older adults over 70: a review.
Abstract Source:
Eur Rev Aging Phys Act. 2015 ;12:8. Epub 2015 Nov 2. PMID: 26865872
Abstract Author(s):
Walid Bouaziz, Elise Schmitt, Georges Kaltenbach, Bernard Geny, Thomas Vogel
Article Affiliation:
Walid Bouaziz
Abstract:
As the number of older adults continues to increase worldwide, more attention is being paid to geriatric health care needs, and successful ageing is becoming an important topic in the medical literature. A preventive approach to the care of older adults is thus a priority in our aging societies. The purpose of this study was to update evidence for the health benefits of cycle ergometer training for older adults over 70. We searched online electronic databases up to September 2014 for original observational and intervention studies on the relationship between cycle ergometer training and health among older patients over 70. Twenty-five studies examined interventions aimed specifically at promoting cycling for older adults over 70. These studies reported a positive effect on the prevention of cardiovascular disease, and a significant improvement in metabolic responses. Improving functional status, muscle strength and cognitive performance are also well established. Overall, this review demonstrates a positive effect of cycle ergometer training with functional benefits and positive health outcomes for older adults over 70. Based on this evidence, clinicians can now encourage older adults to profit from the health benefits of cycle ergometer training to be able to pursue their daily activities independently.
Article Published Date : Dec 31, 2014
Abstract Title:
Caffeine Affects Time to Exhaustion and Substrate Oxidation during Cycling at Maximal Lactate Steady State.
Abstract Source:
Nutrients. 2015 ;7(7):5254-64. Epub 2015 Jun 30. PMID: 26133971
Abstract Author(s):
Rogério Santos de Oliveira Cruz, Rafael Alves de Aguiar, Tiago Turnes, Luiz Guilherme Antonacci Guglielmo, Ralph Beneke, Fabrizio Caputo
Article Affiliation:
Rogério Santos de Oliveira Cruz
Abstract:
This study analyzed the effects of caffeine intake on whole-body substrate metabolism and exercise tolerance during cycling by using a more individualized intensity for merging the subjects into homogeneous metabolic responses (the workload associated with the maximal lactate steady state-MLSS). MLSS was firstly determined in eight active males (25± 4 years, 176 ± 7 cm, 77 ± 11 kg) using from two to four constant-load tests of 30 min. On two following occasions, participants performed a test until exhaustion at the MLSS workload 1 h after taking either 6 mg/kg of body mass of caffeine or placebo (dextrose), in a randomized, double-blindedmanner. Respiratory exchange ratio was calculated from gas exchange measurements. There was an improvement of 22.7% in time to exhaustion at MLSS workload following caffeine ingestion (95% confidence limits of ±10.3%, p = 0.002), which was accompanied by decrease in respiratory exchange ratio (p =0.001). These results reinforce findings indicating that sparing of the endogenous carbohydrate stores could be one of the several physiological effects of caffeine during submaximal performance around 1 h.
Article Published Date : Dec 31, 2014
Abstract Title:
Assisted cycling exercise improves fine manual dexterity in persons with Down's syndrome.
Abstract Source:
J Appl Res Intellect Disabil. 2014 May ;27(3):264-72. Epub 2013 Jun 18. PMID: 23775674
Abstract Author(s):
C-C J J Chen, S D R Ringenbach, A R Albert
Article Affiliation:
C-C J J Chen
Abstract:
BACKGROUND: This study was aimed at investigating the impact of assisted cycling therapy (ACT) on fine manual dexterity in adults with Down's syndrome (DS).
METHODS: Nine persons with DS completed four different interventions: voluntary exercise (VE), voluntary with music (VEM), assisted exercise (AE) and no exercise (NE). Fine manual dexterity (e.g., Purdue Pegboard) was tested pre and post interventions.
RESULTS: The results showed dominant and bimanual hands were improved after AE but no evident in either subtest after VE. The assembly subtest, processed by spatial-temporal ability, was only improved after VEM and NE.
CONCLUSIONS: It is speculated that AE stimulated more peripheral sensory input to the motor cortex and neurotransmitters than the other interventions. In addition, the involvement of music may enhance spatial intelligence during VEM. Even though the exact mechanisms are still unknown, the implication of our results showed that AE and VEM can improve fine manual dexterity in persons with DS.
Article Published Date : Apr 30, 2014
Abstract Title:
The effect of almond consumption on elements of endurance exercise performance in trained athletes.
Abstract Source:
J Int Soc Sports Nutr. 2014 ;11:18. Epub 2014 May 11. PMID: 24860277
Abstract Author(s):
Muqing Yi, Jinde Fu, Lili Zhou, Hong Gao, Chenguang Fan, Jing Shao, Baohua Xu, Qirong Wang, Juntao Li, Guangwei Huang, Karen Lapsley, Jeffrey B Blumberg, C-Y Oliver Chen
Article Affiliation:
Muqing Yi
Abstract:
BACKGROUND: Almonds are a healthy tree nut food with high nutrient density. Their consumption has been shown to ameliorate oxidative stress, inflammation, etc. The objective of the study was to examine the effect of almonds on elements of endurance exercise performance in trained athletes.
METHODS: A 10-week crossover, placebo controlled study was conducted. Eight trained male cyclists and two triathletes were randomly assigned to consume 75 g/d whole almonds (ALM) or isocaloric cookies (COK) with equal subject number. They consumed the assigned food for 4 wks and then the alternate food for another 4 wks. They underwent 3 performance tests including 125-min steady status exercise (SS) and 20-min time trial (TT) on an indoor stationary trainer at the start of the study (BL) and at the end of each intervention phase. Venous blood was collected in the morning prior to the performance test for biochemical measurements and finger blood during the test for glucose determination. Carbohydrate and fat oxidation, energy expenditure, and oxygen use were calculated using respiratory gas analysis.
RESULTS: ALM increased cycling distance during TT by 1.7 km as compared BL (21.9 vs. 20.2 km, P = 0.053) and COK increased 0.6 km (20.8 vs. 20.2 km, P > 0.05). ALM, but not COK, led to higher CHO and lower fat oxidation and less oxygen consumption during TT than BL (P < 0.05), whereas there was no significant difference in heart rate among BL, ALM and COK. ALM maintained higher blood glucose level after TT than COK (P < 0.05). ALM had higher vitamin E and haemoglobin and lower serum free fatty acid (P < 0.05), slightly elevated serum arginine and nitric oxide and plasma insulin (P > 0.05) than BL, and a higher total antioxidant capacity than COK (P < 0.05).
CONCLUSIONS: Whole almonds improved cycling distance and the elements related to endurance performance more than isocaloric cookies in trained athletes as some nutrients in almonds may contribute to CHO reservation and utilization and effective oxygen utilization. The results suggest that almonds can be incorporated into diets of those who undertake exercise training for performance improvement.
Article Published Date : Dec 31, 2013
Abstract Title:
Cycling to school is associated with lower BMI and lower odds of being overweight or obese in a large population-based study of Danish adolescents.
Abstract Source:
J Phys Act Health. 2012 Jul ;9(5):617-25. PMID: 22733866
Abstract Author(s):
Lars Østergaard, Anders Grøntved, Line Anita B Børrestad, Karsten Froberg, Michael Gravesen, Lars B Andersen
Article Affiliation:
Lars Østergaard
Abstract:
BACKGROUND: Previous studies have been inconclusive concerning the effect of active transport on BMI. Our objective was to investigate the association between travel mode and BMI in a large community-based sample of Danish adolescents.
METHODS: A cross-sectional survey on health and lifestyle was distributed to all pupils from the 7th to 9th grade (12-16 years of age) in the municipality of Odense, Denmark.
RESULTS: Cycling to school was associated with 0.38 lower BMI compared to passive travelers (P = .006) after multivariable adjustment. Cycling to school was associated with 0.55 lower odds of being overweight (P<.001) and 0.30 lower (P<.001) odds of being obese compared to individuals using passive transport. Walking to school was associated with 0.65 lower odds of being overweight (P = .006). Post hoc pairwise comparisons of ethnicity revealed that adolescents of foreign ethnicity were more likely to be walkers or passive commuters (75.14% vs. 29.72%) than cyclists (24.86% vs. 70.28%; P<.001) compared to subjects of Danish ethnicity.
CONCLUSIONS: Cycling to school was associated with lower BMI and lower odds of being overweight or obese compared to passive travel in Danish adolescents, whereas walking to school was associated with lower odds of being overweight.
Article Published Date : Jun 30, 2012
Abstract Title:
The effects of honey supplementation on seminal plasma cytokines, oxidative stress biomarkers, and antioxidants during 8 weeks of intensive cycling training.
Abstract Source:
J Androl. 2012 May-Jun;33(3):449-61. Epub 2011 Jun 2. PMID: 21636735
Abstract Author(s):
Bakhtyar Tartibian, Behzad Hajizadeh Maleki
Article Affiliation:
Bakhtyar Tartibian
Abstract:
The purpose of this study was to examine the effects of natural honey supplementation on seminal plasma cytokines, oxidative stress biomarkers, and antioxidants during 8 weeks of intensive cycling training in male road cyclists. Thirty-nine healthy nonprofessional male road cyclists aged 18-28 years participated in this study. The participants were randomly assigned to exercise + supplement (E + S, n = 20) and exercise (E, n = 19) groups. All subjects participated in 8 weeks of intensive cycling training. Ninety minutes before each training session, subjects in the E + S group supplemented with 70 g of honey, whereas subjects in the E group received 70 g of an artificial sweetener. All subjects had an initial semen sampling at baseline (T(1)). The next 6 semen collections were collected immediately (T(2)) and 12 (T(3)) and 24 hours (T(4)) after the last training session in week 4, as well as immediately (T(5)) and 12 (T(6)) and 24 hours (T(7)) after the last training session in week 8, respectively. In the E group, 8 weeks of intensive cycling training significantly increased seminal interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, reactive oxygen species (ROS), and malondialdehyde (MDA) levels (P<.008) and significantly decreased the levels of seminal superoxide dismutase (SOD), catalase, and total antioxidant capacity (TAC) (P<.008). Significantly less elevation in seminal IL-1β, IL-6, IL-8, TNF-α, ROS, and MDA levels (P<.008) and significant increases in seminal SOD, catalase, and TAC concentrations were observed after the honey supplementation in the E + S group (P<.008). It may be possible that honey supplementation following long-term intensive cycling training would be effective in attenuating the probable aggravating effects of intensive cycling training on spermatogenesis and fertility capacity in road cyclists.
Article Published Date : Apr 30, 2012
Abstract Title:
Longitudinal associations between cycling to school and weight status.
Abstract Source:
Int J Pediatr Obes. 2011 Aug ;6(3-4):182-7. Epub 2011 Jun 7. PMID: 21644849
Abstract Author(s):
Elling Bere, Anke Oenema, Richard G Prins, Stephen Seiler, Johannes Brug
Article Affiliation:
Elling Bere
Abstract:
OBJECTIVE: The objective of the present study was to assess the longitudinal association between cycling to school and weight status in two cities where cycling to school is common - Kristiansand (Norway) and Rotterdam (The Netherlands).
METHODS: Data from two studies ENDORSE (Rotterdam) and YOUTH IN BALANCE (Kristiansand) were used. Both studies were longitudinal with two years between time (T) 1 and T2 measurements, and with mean age at T1 of 13.2 and 13.4 years, respectively. The sample was categorized into the following groups according to responses about main mode of commuting to school at the two time points: NO cycling, STARTED cycling, STOPPED cycling and CONTINUED cycling. Measured weight and height were obtained at both time points, and weight status (overweight vs. not overweight) was calculated using international classification criteria for BMI. The two datasets were analyzed separately and together.
RESULTS: In multilevel logistic regression models of the combined sample, adjusting for weight status at Time 1, those who stopped cycling had greater odds of being overweight at T2 (OR = 3.19; 95% CI = 1.41?7.24) while those continued cycling had lower odds of being overweight (OR = 0.44; 95% CI = 0.21?0.88), separately compared to the other three groups together. The same trend was observed in both study samples.
CONCLUSIONS: This study shows that there are longitudinal associations between cycling to school and weight status in two cities where cycling to school is common, implying that interventions aiming at reducing overweight/obesity among adolescents might consider the promotion of sustained cycling behaviour.
Article Published Date : Jul 31, 2011
Abstract Title:
Caffeinated chewing gum increases repeated sprint performance and augments increases in testosterone in competitive cyclists.
Abstract Source:
Eur J Appl Physiol. 2010 Dec;110(6):1243-50. Epub 2010 Aug 25. PMID: 20737165
Abstract Author(s):
Carl D Paton, Timothy Lowe, Athena Irvine
Article Affiliation:
Health and Sport Science, Eastern Institute of Technology, Private Bag 1201, Taradale, Hawkes Bay, Napier, New Zealand. This email address is being protected from spambots. You need JavaScript enabled to view it.
Abstract:
This investigation reports the effects of caffeinated chewing gum on fatigue and hormone response during repeated sprint performance with competitive cyclists. Nine male cyclists (mean ± SD, age 24 ± 7 years, VO(2max) 62.5 ± 5.4 mL kg(-1) min(-1)) completed four high-intensity experimental sessions, consisting of four sets of 30 s sprints (5 sprints each set). Caffeine (240 mg) or placebo was administered via chewing gum following the second set of each experimental session. Testosterone and cortisol concentrations were assayed in saliva samples collected at rest and after each set of sprints. Mean power output in the first 10 sprints relative to the last 10 sprints declined by 5.8 ± 4.0% in the placebo and 0.4 ± 7.7% in the caffeine trials, respectively. The reduced fatigue in the caffeine trials equated to a 5.4% (90% confidence limit ±3.6%, effect size 0.25; ±0.16) performance enhancement in favour of caffeine. Salivary testosterone increased rapidly from rest (~53%) and prior to treatments in all trials. Following caffeine treatment, testosterone increased by a further 12 ± 14% (ES 0.50; ± 0.56) relative to the placebo condition. In contrast, cortisol concentrations were not elevated until after the third exercise set; following the caffeine treatment cortisol was reduced by 21 ± 31% (ES -0.30; ± 0.34) relative to placebo.The acute ingestion of caffeine via chewing gum attenuated fatigue during repeated, high-intensity sprint exercise in competitive cyclists. Furthermore, the delayed fatigue was associated with substantially elevated testosterone concentrations and decreased cortisol in the caffeine trials.
Article Published Date : Dec 01, 2010
Abstract Title:
Dietary arginine supplementation speeds pulmonary VO2 kinetics during cycle exercise.
Abstract Source:
Med Sci Sports Exerc. 2009 Aug;41(8):1626-32. PMID: 19568197
Abstract Author(s):
Katrien Koppo, Youri E Taes, Andries Pottier, Jan Boone, Jacques Bouckaert, Wim Derave
Article Affiliation:
Department of Movement and Sports Sciences, Ghent University, Ghent, Belgium. This email address is being protected from spambots. You need JavaScript enabled to view it.
Abstract:
PURPOSE: To test the hypothesis that L-arginine (the substrate for nitric oxide synthase [NOS]) administration slows the VO2 kinetics at the onset of moderate-intensity exercise in humans.
METHODS: Seven physically active males were randomly assigned to receive either placebo (lactose) or L-arginine hydrochloride capsules (7.2 g x d(-1)) for 14 d in a double-blind crossover design, with a 7-d washout period between the two conditions. On day 11 and day 14 of each condition, the subjects completed two consecutive 6-min bouts of cycle exercise at 80% of the ventilatory threshold with a 12-min rest interval. VO2 was measured on a breath-by-breath basis, and VO2 kinetics were determined with a single exponential model from the averaged data derived from four repetitions. Capillary and venous blood samples were taken to determine plasma [La] and serum [arginine], respectively.
RESULTS: There were no differences in circulating lactate either before or during exercise. However, serum [arginine] was higher (P<0.05) in the arginine condition at rest (119.0 +/- 12.6 vs 103.6 +/- 15.7 micromol x L(-1) in the control condition) and after exercise (113.3 +/- 26.0 vs 103.8 +/- 12.6 micromol x L(-1) in the control condition). With regard to the pulmonary VO2 kinetics, no significant difference was observed in the time at which the phase II response emerged or in the phase II amplitude between the two conditions. However, contrary to our hypothesis, the time constant was significantly reduced after arginine administration (i.e., 13.9 +/- 3.1 vs 15.8 +/- 2.6 s in the control condition, P
CONCLUSION: Exogenous L-arginine administration speeds the phase II pulmonary VO2 response by 12% at the onset of moderate-intensity exercise in humans.
Article Published Date : Aug 01, 2009
Abstract Title:
Cycling and Tai Chi Chuan exercises exert greater immunomodulatory effect on surface antigen expression of human hepatitis B virus.
Abstract Source:
Chin Med J (Engl). 2008 Nov 5;121(21):2172-9. PMID: 19080180
Abstract Author(s):
Yu-Yawn Chen, Jasson Chiang, Yu-Jen Chen, Kung-Tung Chen, Rong-Sen Yang, Jaung-Geng Lin
Abstract:
BACKGROUND: Both athletes with intensive exercise and aged people may have weakened immunity against virus infection. This study aimed to evaluate whether people undergoing aerobic exercises including competitive cyclists with moderate training (CMT) and middle-aged people practicing Tai Chi Chuan (TCC) exercise have higher immunity against hepatitis B virus than age-matched sedentary controls including college students (CSC) and middle-aged people (MSC). METHODS: Human peripheral blood mononuclear cells from competitive cyclists and sedentary controls were stimulated by phytohemagglutinin (PHA) to prepare conditioned medium (MNC-CM) for the assessment of inhibitory effects on hepatitis B surface antigen (HBsAg) expression in human hepatoma Hep3B cells. RESULTS: The inhibitory effects on the relative HBsAg expression of CMT's and TCC's MNC-CM were greater than those of the controls. The CMT's MNC-CM prepared from 5 microg/ml PHA decreased HBsAg expression to 61.5%, whereas that of CSC remained at 83.8%. Similarly, this expression by treatment of TCC group' MNC-CM was 68.4% whereas that of MSC group was 84.3%. The levels of cytokines such as interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), IFN-alpha and interleukin-1beta (IL-1beta) in the MNC-CM from the CMT and TCC groups were greater than those in the controls. Antibody neutralization of CMT's MNC-CM and addition of recombinant cytokines into CSC's MNC-CM indicated that IFN-gamma, TNF-alpha and IFN-alpha had synergistic effects against HBsAg expression. Similar blocking effect was noted in TCC versus MSC groups. CONCLUSION: These results suggest that the immunomodulatory response to suppress HBsAg expression in CMT and TCC with moderate aerobic exercise is greater than that in age-matched sedentary controls.
Article Published Date : Nov 05, 2008
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