EXERCISE

BACKGROUND: Sprint interval cycle training is a contemporary popular mode of training but its relative efficacy, under conditions of matched energy expenditure, to reduce risk factors for cardiometabolic disease is incompletely characterised, especially in young women. The purpose of this investigation was to determine the relative efficacy of six weeks of moderate-intensity cycling (MOD-C) and vigorous sprint-interval cycling (VIG-SIC) on lipid profile, insulin (INS) and insulin resistance using the homeostatic model assessment (HOMA-IR) and C-reactive protein (CRP) in inactive, overweight/obese (OW/OB) young women.

METHODS: Participants (BMI≥25 kg/m(2), waist circumference ≥88 cm) were randomly assigned to MOD-C (20-30 min at 60-70% of heart rate reserve(HRR)) or VIG-SIC (5-7 repeated bouts 30-second maximal effort sprints, followed by four minutes of active recovery) supervised training three days/week for six weeks, with each group matched on energy expenditure. Adiposity (%Fat) was measured using dual x-ray absorptiometry.

RESULTS: Forty-four participants (20.4 ± 1.6 years, 65.9% Caucasian, 29.8 ± 4.1 kg/m(2)) were included in the analysis. The improvement in CRP observed in the MOD-C group was larger than the VIG-C group (p = .034). Overall, high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C) levels improved following training (p < .05); however, total cholesterol, triglyceride, INS and HOMA-IR did not improve (p > .05).

CONCLUSION: These results indicate MOD-C training may be more effective in reducing CRP than VIG-SIC.