HIGH-INTENSITY INTERVAL TRAINING PRODUCES SIMILAR CHANGES TO CONTINUOUS TRAINING, BUT IN MUCH LESS TIME
Dunham, C., & Harms, C. A. (June 03, 2010). The effects of high intensity interval training on pulmonary function. Presentation 2095 at the 2010 Annual Meeting of the American College of Sports Medicine, Baltimore, Maryland; June 2-5.
This study determined if high-intensity interval training would improve respiratory muscle strength and expiratory flow rates more than continuous moderate intensity training. Untrained Ss (N = 13) were randomly assigned to either a high-intensity interval training group (N = 7) or a continuous training group (N = 6). Ss completed a VO2max test, pulmonary function tests (including maximal inspiratory and expiratory pressures), and maximal flow volume loops before and after training. Both groups trained four weeks on a cycle ergometer. The continuous training group trained three times per week for 45 minutes at ~60% VO2max. The high-intensity interval training group performed five one-minute exercise bouts at 90% VO2max separated by three minutes of recovery three times per week. Ss completed a 5-mile time-trial before and after training.
There were no differences between groups in height, weight, pulmonary function tests, VO2max, or time-trial prior to training. Following training, both groups significantly increased VO2max by ~8%. Both groups increased maximal inspiratory and expiratory pressures following training. The high-intensity interval training group had greater maximal inspiratory pressure than the continuous training group. Expiratory flow rates did not change with training. Both groups improved in the time-trial with no between group difference.
Implication. In untrained Ss, whole body exercise training increases inspiratory muscle pressure with high-intensity training eliciting greater effects than continuous moderate intensity exercise. Similar improvements in VO2max and performance in both forms of training, suggests that high-intensity training offers a time-efficient alternative to improving respiratory muscle strength, aerobic capacity, and performance in untrained Ss. [The coaching lore of always starting training with comfortable long-distance work ("to build a training base") takes more participation time to develop the same training effects as could be achieved with moderate loads of high-intensity interval training.]