The aim of this study was to evaluate the safety and potential of PCS as the anti-fatigue functional food. PCS was prepared by water extracting-alcohol precipitating method, and its chemical compositions of monosaccharide were analyzed. Then, acute toxicity and anti-fatigue activity of PCS were evaluated. PCS is composed of Rha, Arab, Xyl, Man, Glu, and Gal, its molar ratio is 0.17: 0.30: 0.26: 0.35: 1.00: 0.57. No mortality and general symptoms of toxicity were observed in the PCS treated mice (7.5, 15, and 20g/kg body weight), the body weight and food consumption were not significantly changed compared with the normal control group. The relative weights of main organ, and biochemical indicators also did not markedly change. PCS can significantly prolong the duration of the swimming time to exhaustion in mice, decrease BUN, LA levels, increase LDH activities, and the contents of HG in the PCS treated mice. The dose of 400mg/kg body weight is the optimal dose for anti-fatigue activity both in male and female mice. In conclusion, PCS is a promising traditional natural-based therapeutic remedy for relieving fatigue with high safety.

OBJECTIVE:To examine the anti-fatigue function of anwulignan from Schisandra and its underlying mechanism.

METHODS:After an excessive fatigue mouse model was created, anwulignan was administered to the mice, and its effect on exercise tolerance was studied by the weight-bearing swimming test, rotarod test, grip strength test, and tail suspension test. The biochemical indicators closely related to fatigue, including blood urea nitrogen (BUN), lactic acid (LD), lactate dehydrogenase (LDH), and creatine kinase (CK) in the serum; liver glycogen (LG) in the liver tissue; muscle glycogen (MG); inorganic phosphate (Pi) and Annexin V in the gastrocnemius; superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities; malondialdehyde (MDA), catalase (CAT), and thiobarbituric acid reactive substances (TBARS); and the 8-hydroxy-2-deoxyguanosine (8-OHdG) and reactive oxygen species (ROS) content in both serum and the gastrocnemius were detected. Morphological changes were also observed. The anti-fatigue-related proteins of the NRF2/ARE, Bcl2, and PGC-1α pathways in the gastrocnemius of the mice were detected by western blot.

RESULTS:Anwulignan significantly increased the exercise tolerance by decreasing BUN, LD, LDH, CK, Pi, MDA, TBARS, 8-OHdG, ROS, and Annexin V levels and increasing LG, MG, SOD, CAT, and GSH-Px levels, significantly upregulated the expression of NRF2 and Bcl2 proteins, which are anti-oxidation and anti-apoptosis regulators, and also activated the p38MAPK-PGC-1α pathway.

CONCLUSION:Anwulignan can increase exercise tolerance and relieve fatigue in an excessive fatigue mouse model. The underlying mechanism may be through its regulatory effect on the NRF2 and PGC-1α signaling pathway. This study will provide scientific data for anwulignan to be developed as a novel and efficient component in anti-oxidant or anti-fatigue health food.

We aimed to determine the effects of a betalain-rich concentrate (BRC) of beetroots, containing no sugars or nitrates, on exercise performance and recovery. Twenty-two (9 men and 13 women) triathletes (age, 38± 11 years) completed 2 double-blind, crossover, randomized trials (BRC and placebo) starting 7 days apart. Each trial was preceded by 6 days of supplementation with 100 mg·day(-1) of BRC or placebo. On the 7th day of supplementation, exercise trials commenced 120 min after ingestion of 50 mg BRCor placebo and consisted of 40 min of cycling (75 ± 5% maximal oxygen consumption) followed by a 10-km running time trial (TT). Subjects returned 24 h later to complete a 5-km running TT to assess recovery. Ten-kilometer TT duration (49.5 ± 8.9 vs. 50.8 ± 10.3 min, p = 0.03) was faster with the BRC treatment. Despite running faster, average heart rate and ratings of perceived exertion were not different between treatments. Five-kilometer TT duration (23.2 ± 4.4 vs 23.9 ± 4.7 min, p = 0.003), 24 h after the 10-km TT, was faster in 17 of the 22 subjects with the BRC treatment. Creatine kinase, a muscle damage marker, increased less (40.5 ± 22.5 vs. 49.7 ± 21.5 U·L(-1), p = 0.02) from baseline to after the 10-km TT and subjective fatigue increased less (-0.05 ± 6.1 vs. 3.23 ± 6.1, p = 0.05) from baseline to 24 h after the 10-km TT with BRC. In conclusion, BRC supplementation improved 10-km TT performance in competitive male and female triathletes. Improved 5-km TT performances 24 h after the 10-km TT and the attenuated increase of creatine kinase and fatigue suggest an increase in recovery while taking BRC.

The aim of this study was to investigate the plasma dopamine and serum serotonin levels in humans with and without caffeine (CAFF) ingestion during treadmill running exercise. Thirty male volunteers participated in the randomized experiment involving two groups: CON (n = 15, 200 mL of tap water) versus CAFF (n = 15, 3 mg/kg CAFF and 200 mL tap water). After treadmill running, the dopamine level was significantly increased in the CAFF group (P<0.01) and was significantly higher than in the CON group (P<0.01). Serotonin was significantly increased in both groups after treadmill running (P<0.05). However, serotonin levels showed no significant statistical difference between the groups. Prolactin and cortisol were significantly increased in both groups after treadmill running (P<0.01). However, there was no significant statistical difference between groups.β-endorphin level was significantly increased in the CAFF group at after treadmill running (P<0.01) and was significantly higher than in CON after treadmill running (P<0.01). In conclusion, 3 mg/kg CAFF ingestion before treadmill running stimulated dopamine release without inhibiting serotonin, which may reduce central fatigue.

:The temporal structure, or complexity, of muscle torque output decreases with neuromuscular fatigue. The role of central fatigue in this process is unclear.

PURPOSE:We tested the hypothesis that caffeine administration would attenuate the fatigue-induced loss of torque complexity.

METHODS:Eleven healthy participants performed intermittent isometric contractions of the knee extensors to task failure at a target torque of 50% maximal voluntary contraction (MVC), with a 60% duty factor (6 s contraction, 4 s rest), 60 min after ingesting 6 mg·kg caffeine or a placebo. Torque and surface EMG signals were sampled continuously. Complexity and fractal scaling of torque were quantified using approximate entropy (ApEn) and the detrended fluctuation analysis (DFA) α scaling exponent. Global, central and peripheral fatigue were quantified using MVCs with femoral nerve stimulation.

RESULTS:Caffeine ingestion increased endurance by 30± 16% (mean ± SD, P = 0.019). Complexity decreased in both trials (decreased ApEn, increased DFA α; both P<0.01), as global, central and peripheral fatigue developed (all P<0.01). Complexity decreased significantly more slowly following caffeine ingestion (ApEn, -0.04± 0.02 vs. -0.06 ± 0.01, P = 0.004; DFA α, 0.03 ± 0.02 vs. 0.04 ± 0.03, P = 0.024), as did the rates of global (-18.2 ± 14.1 vs. -23.0 ± 17.4 N.m.min, P = 0.004) and central (-3.5 ± 3.4 vs. -5.7 ± 3.9 %·min, P = 0.02) but not peripheral (-6.1 ± 4.1 vs. -7.9 ± 6.3 N.m.min, P = 0.06) fatigue.

CONCLUSION:Caffeine ingestion slowed the fatigue-induced loss of torque complexity and increased the time to task failure during intermittent isometric contractions, most likely through central mechanisms.

In this study,mycelia (CVM) was evaluated the ergogenic and anti-fatigue activities. Male ICR mice were divided into four groups (= 8/group) to receive vehicle or CVM by oral gavage for 4 weeks at 0, 615, 1230 or 3075 mg/kg/day, which were respectively designated the vehicle, CVM-1X, CVM-2X and CVM-5X groups. Forelimb grip strength, endurance swimming time, and levels of physical fatigue-associated parameters serum lactate, ammonia, glucose and creatine kinase (CK) after physical challenge were performed to evaluate exercise performance and anti-fatigue activity. Results revealed that the forelimb grip strength of mice in group CVM-1X, CVM-2X and CVM-5X were significantly increased by 1.20-, 1.18- and 1.23-fold, respectively, compared to the vehicle group. After the 15 minute swimming exercise, the levels of serum lactate of CVM-1X, CVM-2X and CVM-5X groups were significantly lower than the vehicle control group by 29%, 23% and 31%, respectively. The levels of ammonia in CVM-1X, CVM-2X and CVM-5X groups were significantly lowered by 22%, 25% and 41%, respectively, compared to the vehicle control group. In addition, the levels of serum CK in CVM-2X and CVM-5X groups were significantly lowered by 13% and 11%, respectively, compared to the vehicle control group. Accordingly, the supplementation with CVM has beneficial effects on performance improvement and anti-fatigue activity, and thus has great potential as a source for natural health products.

Probiotics have been rapidly developed for health promotion, but clinical validation of the effects on exercise physiology has been limited. In a previous study,TWK10 (TWK10), isolated from Taiwanese pickled cabbage as a probiotic, was demonstrated to improve exercise performance in an animal model. Thus, in the current study, we attempted to further validate the physiological function and benefits through clinical trials for the purpose of translational research. The study was designed as a double-blind placebo-controlled experiment. A total of 54 healthy participants (27 men and 27 women) aged 20-30 years without professional athletic training were enrolled and randomly allocated to the placebo, low (3× 10colony forming units (CFU)), and high dose (9× 10CFU) TWK10 administration groups (= 18 per group, with equal sexes). The functional and physiological assessments were conducted by exhaustive treadmill exercise measurements (85% VO), and related biochemical indices were measured before and after six weeks of administration. Fatigue-associated indices, including lactic acid, blood ammonia, blood glucose, and creatinine kinase, were continuously monitored during 30 min of exercise and a 90 min rest period using fixed intensity exercise challenges (60% VO) to understand the physiological adaptation. The systemic inflammation and body compositions were also acquired and analyzed during the experimental process. The results showed that TWK10 significantly elevated the exercise performance in a dose-dependent manner and improved the fatigue-associated features correlated with better physiological adaptation. The change in body composition shifted in the healthy direction for TWK10 administration groups, especially for the high TWK10 dose group, which showed that body fat significantly decreased and muscle mass significantly increased. Taken together, our results suggest that TWK10 has the potential to be an ergogenic aid to improve aerobic endurance performance via physiological adaptation effects.

Antrodia camphorata and Panax ginseng are well-known medicinal plants in Taiwan folk and traditional Chinese medicine, which have been reported for multifunctional bioactivities. However, there is limited evidence that a fixed combination formula of these two plant extracts is effective for the exercise improvement or anti-fatigue. We aimed to evaluate the potential beneficial effects of the mix formulation of these two herbal medicines (AG formulation) on fatigue and ergogenic functions following physiological challenge. Male Institute of Cancer Research (ICR) mice from four groups (n=10 per group) were orally administered AG formulation for 4 weeks at 0.984, 2.952 and 5.904 g/kg/day, which were designated the Vehicle, AG-1X, AG-3X and AG-6X groups, respectively. The anti-fatigue activity and exercise performance were evaluated using exhaustive swimming time, forelimb grip strength, and levels of serum lactate, ammonia, glucose, blood urea nitrogen (BUN) and creatine kinase (CK) after a swimming exercise. The exhaustive swimming time of the 1X, 3X or 6X AG group was significantly longer than that of the Vehicle group, and the forelimb grip strength of the 1X, 3X or 6X AG group was also significantly higher than that of the Vehicle group. AG supplementation also produced decreases in serum lactate, ammonia, BUN and CK activity after the swimming test, as well as increases in glucose. Therefore, the AG complex could be a potential formulation with an anti-fatigue pharmacological effect.

BACKGROUND:Recent studies showed a positive effect of hydrogen rich water (HRW) intake on acid-base homeostasis at rest. We investigated 2-weeks of HRW intake on repeated sprint performance and acid-base status during prolonged intermittent cycling exercise.

METHODS:In a cross over single-blind protocol, 8 trained male cyclists (age [mean±SD] 41±7 years, body mass 72.3±4.4 kg, height 1.77±0.04 m, maximal oxygen uptake [V̇O2max] 52.6±4.4 mL·kg-1·min-1) were provided daily with 2 liters of placebo normal water (PLA, pH 7.6, oxidation/reduction potential [ORP] +230 mV, free hydrogen content 0 ppb) or HRW (pH 9.8, ORP -180 mV, free Hydrogen 450 ppb). Tests were performed at baseline and after each period of 2 weeks of treatment. The treatments were counter-balanced and the sequence randomized. The 30-minute intermittent cycling trial consisted in 10 3-minute blocks, each one composed by 90 seconds at 40% V̇O2max, 60 seconds at 60% V̇O2max, 16 seconds all out sprint, and 14 seconds active recovery. Oxygen uptake (V̇O2), heart rate and power output were measured during the whole test, while mean and peak power output (PPO), time to peak power and Fatigue Index (FI) were determined during all the 16 seconds sprints.Lactate, pH and bicarbonate (HCO3-) concentrations were determined at rest and after each sprint on blood obtained by an antecubital vein indwelling catheter.

RESULTS:In the PLA group, PPO in absolute values decreased significantly at the 8th and 9th of 10 sprints and in relative values,ΔPPO, decreased significantly at 6th, 8th and 9th of 10 sprints (by mean: -12±5%, P<0.006), while it remained unchanged in HRW group. Mean power, FI, time to peak power and total work showed no differences between groups. In both conditions lactate levels increased while pH and HCO3- decreased progressively as a function of the number of sprints.

CONCLUSIONS:Two weeks of HRW intake may help to maintain PPO in repetitive sprints to exhaustion over 30 minutes.

Background:Exhaustive exercise causes muscle damage accompanied by oxidative stress and inflammation leading to muscle fatigue and muscle soreness. Lemon verbena leaves, commonly used as tea and refreshing beverage, demonstrated antioxidant and anti-inflammatory properties. The aim of this study was to investigate the effects of a proprietary lemon verbena extract (Recoverben®) on muscle strength and recovery after exhaustive exercise in comparison to a placebo product.

Methods:The study was performed as a randomized, placebo-controlled, double-blind study with parallel design. Forty-four healthy males and females, which were 22-50 years old and active in sports, were randomized to 400 mg lemon verbena extract once daily or placebo. The 15 days intervention was divided into 10 days supplementation prior to the exhaustive exercise day (intensive jump-protocol), one day during the test and four days after. Muscle strength (MVC), muscle damage (CK), oxidative stress (GPx), inflammation (IL6) and volunteer-reported muscle soreness intensity were assessed pre and post exercise.

Results:Participants in the lemon verbena group benefited from less muscle damage as well as faster and full recovery. Compared to placebo, lemon verbena extract receiving participants had significantly less exercise-related loss of muscle strength ( = 0.0311) over all timepoints, improved glutathione peroxidase activity by trend ( = 0.0681) and less movement induced pain ( = 0.0788) by trend. Creatine kinase and IL-6 didn't show significant discrimmination between groups.

Conclusion:Lemon verbena extract (Recoverben®) has been shown to be a safe and well-tolerated natural sports ingredient, by reducing muscle damage after exhaustive exercise.

Trial registration:The trial was registered in the clinical trials registry (clinical trial.gov NCT02923102). Registered 28 September 2016.

Background:Grape seed proanthocyanidin extract (GSPE) has been extensively reported to possess a wide range of beneficial properties in multiple tissue damage. Previous studies have shown that exhaustive exercise-induced fatigue associates with oxidative stress injury, inflammatory response, and mitochondrial dysfunction.

Objective:The aim of this study is to investigate the anti-fatigue effects of GSPE in mice and explore its possible underlying mechanism.

Design:The mouse model of exhaustive exercise-induced fatigue was established by using the forced swimming test, and GSPE was orally treated for successive 28 days at 0, 1, 50 and 100 mg/kg/day of body weight, designated the control, GSPE-L, GSPE-M and GSPE-H groups, respectively.

Results:The presented results showed that treatment of GSPE at a dose of 50 and 100 mg/kg/day of body weight significantly relieved exhaustive exercise-induced fatigue, indicated by increasing the forced swimming time. In addition, treatment of GSPE significantly improved the creatine phosphokinase and lactic dehydrogenase, as well as lactic acid level in exhaustive swimming. For underlying mechanisms, treatment of GSPE had anti-fatigue effects by promoting antioxidant ability and resisting oxidative effect, as represented by increased total antioxidative capability levels, enhanced superoxide dismutase and catalase activities, and ameliorated malondialdehyde levels. Furthermore, treatment of GSPE significantly inhibited the activity of tumor necrosis factor-α and interleukin-1β, which suggested that its protective effects on exhaustive exercise-induced fatigue may be attributed to inhibition of inflammatory response. Last but not the least, treatment of GSPE significantly improved succinate dehydrogenase and Na+-K+-ATPase levels to enhance mitochondrial function during exhaustive swimming-induced fatigue.

Conclusions:These results proved that treatment of GSPE possessed the beneficial properties of anti-inflammatory, antioxidant, and mitochondrial protection to improve exhaustive exercise, which suggested that GSPE could be used as an effective functional food to delay fatigue.

This study evaluated the ingestion of sodium bicarbonate (NaHCO3) on post-exercise acid-base balance recovery kinetics and subsequent high-intensity cycling time to exhaustion. In a counterbalanced, crossover design, nine healthy and active males (age: 23±2 years, height: 179±5 cm, body mass: 74±9 kg, peak mean minute power (WPEAK) 256±45 W, peak oxygen uptake (V̇O2PEAK) 46±8 ml.kg(-1).min(-1)) performed a graded incremental exercise test, two familiarisation and two experimental trials. Experimental trials consisted of cycling to volitional exhaustion (TLIM1) at 100% WPEAK on two occasions (TLIM1 and TLIM2) interspersed by a 90 min passive recovery period. Using a double blind approach, 30 min into a 90 min recovery period participants ingested either 0.3 g.kg(-1) body mass sodium bicarbonate (NaHCO3) or a placebo (PLA) containing 0.1 g.kg(-1) body mass sodium chloride (NaCl) mixed with 4 ml.kg(-1) tap water and 1 ml.kg(-1) orange squash. The mean differences between TLIM2 and TLIM1 was larger for PLA compared to NaHCO3 (-53±53 vs. -20±48 s; P=0.008, d=0.7, CI=-0.3, 1.6), indicating superior subsequent exercise time to exhaustion following NaHCO3. Blood lactate [BLa(-)] was similar between treatments post TLIM1, but greater for NaHCO3 post TLIM2 and 5 min post TLIM2. Ingestion of NaHCO3 induced marked increases (P<0.01) in both blood pH (+0.07±0.02, d=2.6, CI=1.2, 3.7) and bicarbonate ion concentration [HCO3(-)] (+6.8±1.6 mmo.l(-1), d=3.4, CI=1.8, 4.7) compared to the PLA treatment, prior to TLIM2. It is likely both the acceleration of recovery, and the marked increases of acid-base after TLIM1 contributed to greater TLIM2 performancecompared to the PLA condition.

The present study evaluated the potential beneficial effect of kefir (KF) against fatigue. Furthermore, the composition of the gut microbiota is related to health benefits in the host; therefore, the study also investigated the effect of KF on the gut microbiota composition. Male ICR mice from four groups (= 8 per group) were orally administered KF once daily for four weeks at 0, 2.15, 4.31, and 10.76 g/kg/day and were designated as the vehicle, KF-1X, KF-2X, and KF-5X groups, respectively. The gut microbiota was analyzed using 16S rRNA gene sequencing. The results showed a significant clustering of cecum after treatment in the vehicle, KF-1X, KF-2X, and KF-5X groups. The KF-2X and KF-5X groups showed a decreased/ratio compared with the vehicle group. In addition, anti-fatigue activity and exercise performance were evaluated on the basis of exhaustive swimming time, forelimb grip strength, and levels of serum lactate, ammonia, glucose, blood urea nitrogen (BUN), and creatine kinase (CK) after a swimming exercise. The exhaustive swimming time for the KF-1X, KF-2X, and KF-5X groups was significantly longer than that for the vehicle group, and the forelimb grip strength of the KF-1X, KF-2X, and KF-5X groups was also significantly higher than that of the vehicle group. KF supplementation also decreased serum lactate, ammonia, BUN, and CK levels after the swimming test. However, tissue glycogen content, an important energy source for exercise, increased significantly with KF supplementation. Thus, KF supplementation can alter the gut microbiota composition, improve performance, and combat physical fatigue.

In previous studies, Nigella sativa (NS) has been studied due to its various physiological and pharmacological activities. However, evidence on the effects of NS on physical fatigue following exhaustive swimming remains limited. In the present study, the authors evaluated the potential beneficial effects of NS against the fatigue activity following exhaustive swimming. Rats were orally administered with NS extract (2 g/kg/day) for 21 days, and the anti-fatigue effect was assessed by exhaustive swimming exercise. The presented results indicated that pre-treatment of NS extract significantly increased the time to exhaustion. In hemodynamic parameters, NS extract increased blood pO2 and O2sat, but decreased pCO2. For underlying mechanisms, NS extract protected depletion of energy, indicated by increased levels of blood pH, glucose and tissue glycogen contents, and decreased levels of blood lactate, tissue lactic dehydrogenase and creatine kinase, when the NS extract was pre-treated. In addition, the NS extract inhibited oxidative stress following exhaustive swimming, as reflected by the results of increased levels of superoxide dismutase and redox ratio, and decreased the level of malondialdehyde when the NS extract was pre-treated. Collectively, the present study demonstrated that NS extract has an anti-fatigue activity against exhaustive swimming by energy restoration and oxidative-stress defense.

BACKGROUND:Muscle contraction during short intervals of intense exercise causes oxidative stress, which can play a role in the development of overtraining symptoms, including increased fatigue, resulting in muscle microinjury or inflammation. Recently it has been said that hydrogen can function as antioxidant, so we investigated the effect of hydrogen-rich water (HW) on oxidative stress and muscle fatigue in response to acute exercise.

METHODS:Ten male soccer players aged 20.9 ± 1.3 years old were subjected to exercise tests and blood sampling. Each subject was examined twice in a crossover double-blind manner; they were given either HW or placebo water (PW) for one week intervals. Subjects were requested to use a cycle ergometer at a 75 % maximal oxygen uptake(VO2) for 30 min, followed by measurement of peak torque and muscle activity throughout 100 repetitions of maximal isokinetic knee extension. Oxidative stress markers and creatine kinase in the peripheral blood were sequentially measured.

RESULTS:Although acute exercise resulted in an increase in blood lactate levels in the subjects given PW, oral intake of HW prevented an elevation of blood lactate during heavy exercise. Peak torque of PW significantly decreased during maximal isokinetic knee extension, suggesting muscle fatigue, but peak torque of HW didn't decrease at early phase. There was no significant change in blood oxidative injury markers (d-ROMs and BAP) or creatine kinease after exercise.

CONCLUSION:Adequate hydration with hydrogen-rich water pre-exercise reduced blood lactate levels and improved exercise-induced decline of muscle function. Although further studies to elucidate the exact mechanisms and the benefits are needed to be confirmed in larger series of studies, these preliminary results may suggest that HW may be suitable hydration for athletes.

OBJECTIVE:To investigate the roles of BDNF/TrkB neurotrophic signaling in hippocampal injury for fatigue rats induced by incremental load exercise and the protective effects and mechanism of spirulina supplement.

METHODS:Sixty SD rats were randomly divided into normal control group (NC), normal plus spirulina group(NS), exercise model group (EM), exercise plus spirulina group (ES), and positive control group (PC), 12 rats in each group.Group EM, Group ES and Group PC were applied by treadmill running with high-intensity increasing for three weeks, and Group NC had not any intervention measures.Group ES and Group NS were treated with spirulina at a dose of 300 mg/kg.bw.by intragastric administration.Group PC was gavaged at the same volume of ginseng extract of 1.92 g/kg for three weeks.The expressions of brain-derived neurotrophic factor (BDNF), tyrosine kinase recptor (TrkB), phospho-tyrosine kinase recptor (p-TrkB) were tested by Western blot and immunohistochemical method, and micromorphology changes of hippocampal CA1 were observed by light microscope at the end of the experiment.The general situations of rats such as body weights were recorded during the experiment.

RESULTS:Compared with Group NC, Group EM showed significantly decrease in body weight and hippocampal CA1 neurons of the group loosely arrayed and disarrayed and some neurons were shrinked, and even some neurons disappeared.The expressions of BDNF, TrkB and p-TrkB in group EM were increased significantly(<0.01).Compared with Group EM, body weight of Group ES was increased significantly, and the above mentioned injuries of neurons were improved significantly:the number of neurons and nissl bodies were significantly increased and the neurons arrayed regularly and its morphology was more complete.The expressions of BDNF, TrkB and p-TrkB in the group were increased significantly(<0.05 or<0.01).And there was no difference between Group ES and Group PC.

CONCLUSIONS:BDNF/TrkB neurotrophic signal pathway could be involved in the repair process of hippocampal nervous damage caused by incremental load exercise for fatigue rats.Spirulina supplement had a protective effect on the damaged nervous through increasing the expressions of BDNF, TrkB and p-TrkB.

BACKGROUND:Sodium bicarbonate intake has been shown to improve exercise tolerance, but the effects on high-intensity intermittent exercise are less clear. Thus, the aim of the present study was to determine the effect of sodium bicarbonate intake on Yo-Yo intermittent recovery test level 2 performance in trained young men.

METHOD:Thirteen men aged 23 ± 1 year (height: 180 ± 2 cm, weight: 78 ± 3 kg; VO2max: 61.3 ± 3.3 mlO2 · kg(-1) · min(-1); means ± SEM) performed the Yo-Yo intermittent recovery test level 2 (Yo-Yo IR2) on two separate occasions in randomized order with (SBC) and without (CON) prior intake ofsodium bicarbonate (0.4 g · kg(-1) body weight). Heart rate and rating of perceived exertion (RPE) were measured during the test and venous blood samples were taken frequently.

RESULTS:Yo-Yo IR2 performance was 14 % higher (P = 0.04) in SBC than in CON (735 ± 61 vs 646 ± 46 m, respectively). Blood pH and bicarbonate were similar between trials at baseline, but higher (P = 0.003) immediately prior to the Yo-Yo IR2 test in SBC than in CON (7.44 ± 0.01 vs 7.32 ± 0.01 and 33.7 ± 3.2 vs 27.3 ± 0.6 mmol · l(-1), respectively). Blood lactate was 0.9 ± 0.1 and 0.8 ± 0.1 mmol · l(-1) at baseline and increased to 11.3 ± 1.4 and 9.4 ± 0.8 mmol · l(-1) at exhaustion in SBC and CON, respectively, being higher (P = 0.03) in SBC. Additionally, peak bloodlactate was higher (P = 0.02) in SBC than in CON (11.7 ± 1.2 vs 10.2 ± 0.7 mmol · l(-1)). Blood glucose, plasma K(+) and Na(+) were not different between trials. Peak heart rate reached at exhaustion was 197 ± 3 and 195 ± 3 bpm in SBC and CON, respectively, with no difference between conditions. RPE was 7% lower (P = 0.003) in SBC than in CON after 440 m, but similar at exhaustion (19.3 ± 0.2 and 19.5 ± 0.2).

CONCLUSION:In conclusion, high-intensity intermittent exercise performance is improved by prior intake of sodium bicarbonate in trained young men, with concomitant elevations in blood alkalosis and peak blood lactate levels, as well as lowered rating of perceived exertion.

It has been reported that abundant nitric oxide content in endothelial cells can increase exercise performance. The purpose of this study was to evaluate the potential beneficial effects of a combined extract comprising L-arginine, L-glutamine, vitamin C, vitamin E, folic acid, and green tea extract (LVFG) on nitric oxide content to decrease exercise fatigue. Male ICR (Institute of Cancer Research) mice were randomly divided into 4 groups and orally administered LVFG for 4 weeks. The 4-week LVFG supplementation significantly increased serum nitric oxide content in the LVFG-1X and LVFG-2X groups. Antifatigue activity and exercise performance were evaluated using forelimb grip strength, exhaustive swimming test, and levels of serum lactate, ammonia, glucose, and creatine kinase (CK) after an acute swimming exercise. LVFG supplementation dose-dependently improved exercise performance and nitric oxide content, and it dose-dependently decreased serum ammonia and CK activity after exhaustive swimming test. LVFG's antifatigue properties appear to manifest by preserving energy storage (as blood glucose) and increasing nitric oxide content. Taken together, our results show that LVFG could have the potential for alleviating physical fatigue due to its pharmacological effect of increasing serum nitric oxide content.

Hualian No. 4 wild bitter gourd (WBG) is a specific vegetable cultivated by the Hualien District Agricultural Research and Extension Station in Taiwan. WBG is commonly consumed as a vegetable and used as a popular folk medicine. However, few studies have demonstrated the effects of WBG supplementation on exercise performance, physical fatigue and the biochemical profile. The purpose of this study was to evaluate the potential beneficial effects of WBG extract on fatigue and ergogenic functions following physiological challenge. Three groups of male ICR mice (n=8 per group) were orally administered 0, 1 or 2.5 g/kg/day of WBG for 4 weeks. They were respectively designated the vehicle, WBG-1X and WBG-2.5X groups. WBG significantly decreased body weight (BW) and epididymal fat pad (EFP) weight. Concerning physical performance, WBG supplementation dose-dependently increased grip strength and endurance swimming time. Concerning anti-fatigue activity, WBG decreased levels of serum lactate, ammonia, creatine kinase and blood urea nitrogen, and economized glucose metabolism after acute exercise challenge. Glycogen in the liver and gastrocnemius muscle dose-dependently increased with WBG treatment. Concerning the biochemical profile, WBG treatment significantly decreased alanine aminotransferase (ALT), blood urea nitrogen (BUN), urea acid (UA), and increased total protein (TP). Therefore, 4-week supplementation with WBG may decrease white adipose weight, enhance energy economy, increase glycogen storage to enhance exercise performance and reduce fatigue.

) was shown to recover fatigue and imbalanced immune system. Therefore, effect of chronic administration ofhydroethanolic extract on splenocytes response in sedentary and exercised animals, was evaluated. Male Wistar rats were randomly divided into non-treated (control sedentary (C), moderately trained (MT; Velocity 20 m/min, 30 min/day 8 weeks), and over-trained (OT; Velocity 25 m/min, 60 min/day 11 weeks)), andtreated animals (Nisa, 200 mg/kg, orally) (control (Nisa-C), moderately trained (Nisa-MT) and over-trained (Nisa-OT)). Finally, cell viability and proliferation, as well as interleukin 4 (IL-4) and interferon-γ (IFN-γ) secretion in non-stimulated and concanavalin A (Con A)-stimulated splenocytes, were evaluated. In the absence of the mitogen, cell viability in Nisa-C and Nisa-OT, cell proliferation in Nisa-C and Nisa-MT, IFN-γ concentration in Nisa-MT and Nisa-OT and IFN-γ/IL-4 ratio in Nisa C, Nisa-MT and Nisa-OT were higher compared to non-treated groups; but, IL-4 level in Nisa-MT was lower than non-treated groups. In the presence of the mitogen, cell viability in Nisa-C and Nisa-OT, IL-4 concentration in Nisa-C and Nisa-OT groups, and IFN-γ concentration and IFN-γ/IL-4 ratio in Nisa-MT were higher, while IFN-γ/IL-4 ratio was lower in Nisa-C group compared to non-treated groups. Moreover, IFN-γ/IL-4ratio in stimulated and non-stimulated splenocytes supernatant was higher in Nisa-MT compared to Nisa-C and Nisa-OT groups.chronic administration may shift Th1/Th2 cytokines profile of splenocytes towards Th1, especially in over-trained and non-stimulated condition. Moderate exercise andsupplementation may improve disorders associated with elevated Th2 such as overtraining syndrome.