Effects of high-intensity interval training combined with blood flow restriction on aerobic fitness, fatigue tolerance and cycling performance in master road cyclists
Abstract:
The purpose of this study was to investigate and compare the effects of usual training (UST), high-intensity interval training (HIIT), high-intensity interval training combined with blood flow restriction (HIIT+BFR) for 12 weeks on aerobic fitness, fatigue tolerance and cycling performance in master road cyclists. Fifty male master road cyclists (aged 35 to 49 years) were randomly assigned into three groups : 1) UST (continuous cycling training at 75 min at 65 to 70% PPO; n=16), 2) HIIT (4x4 min interval at 80% PPO alternated with 2 min at 30% PPO on a modified cycle ergometer; n=17), and 3) HIIT+BFR (similar to HIIT, except the 2nd and 4th bout the intensities were reduced to 60% PPO and BFR cuff at 30% AOP; n=17). All groups performed cycling training 6 days/weeks including group specific training 2 days/week as well as continuous cycling training for 120 min at ~55-60% PPO for 2 days/week and for 75 min at ~65-70% PPO, 2 days/week for 12 weeks. Physiological data, aerobic fitness, muscular fitness, vascular structure and function, muscular structure and function, blood chemistry, and cycling performance were measured. The 2x3 (Group x times) ANOVA with repeated measures followed by Fishers Least Significant Difference multiple comparisons were used to determine the significant difference in all variables before and after training and among groups. After 12 weeks, maximal oxygen consumption, ventilator threshold, maximal cardiac output, maximal stroke volume, cutaneous blood flow (foot), peak torque of knee flexion, and 40 km time trial performance increased in all groups (all p<0.05). There were no significant changes in carotid artery intima-media thickness, arterial stiffness, creatine phosphokinase, and nitric oxide in all three groups. Peak power output, brachial and popliteal FMD, time to fatigue and average power of time trial 40 km increased in both HIIT and HIIT+BFR groups (all p<0.05). Total and leg lean mass, muscle cross-sectional area and thickness in rectus femoris and vastus lateralis, peak torque of knee extension, work of knee extension and flexion, tissue oxygenation index, deoxyhemoglobin, Insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF) and blood lactate removal rate after time trial 40 km increased only in the HIIT+BFR group (all p<0.05). In conclusion, high-intensity interval training combined with blood flow restriction has found to be safe and effective to improve aerobic fitness, muscular fitness, vascular functions and cycling performance in master road cyclists.