Aerobic Fitness Changes In Trained And Untrained Subjects Following A Three Week Cycling Course

PURPOSE: We determined the effect of a 5BX-style program on peak oxygen uptake (VO2peak) in inactive but healthy young men and women (20±1 y; body mass index: 20±5 kg/m ; mean±SD). METHODS: Participants were randomized to a training group that performed 18 sessions over six weeks (n=9), or a non-training control group (n=10). Each session involved a 1-minute warm-up (jumping jacks), followed by 1-minute bouts of five exercises (burpees, high knees, split squat jumps, high knees, squat jumps), each interspersed with 1-minute of active recovery (walking around the room). Participants were instructed to complete as many repetitions per bout as possible, at a self-determined ―challenging‖ pace. All sessions were supervised and compliance was 100%. RESULTS: Mean intensity during training was 82±5% of maximal heart rate. Borg Scale ratings of perceived exertion for the five exercises ranged from 12±2 to 15±3 out of 20. ANCOVA revealed a significant difference between groups after the intervention, such that VO2peak was higher in the training group compared to control (34.2±6.4 vs 30.3±11.1 ml/kg/min; P=0.03). Peak power output during the VO2peak test was also higher after training compared to control (211±43 vs 191±50 W, p=0.004). There were no changes in leg muscular endurance, handgrip strength or vertical jump height in either group. CONCLUSIONS: A simple bodyweight interval training program, requiring 11 minutes per session, increased cardiorespiratory fitness in previously sedentary young adults when performed three times per week for six weeks. Supported by NSERC.