Four-Second Power Cycling Training Increases Maximal Anaerobic Power, Peak Oxygen Consumption, and Total Blood Volume.

INTRODUCTION High-intensity interval training (HIIT) is an effective tool to improve cardiovascular fitness and maximal anaerobic power. Different methods of HIIT have been studied but the effects of repeated maximal effort cycling with very short exercise time (i.e., 4-s) and short recovery time (15-30 s) might suit individuals with limited time to exercise. PURPOSE We examined the effects of training at near maximal anaerobic power during cycling (PC) on maximal anaerobic power, peak oxygen consumption (VO2peak), and total blood volume in 11 young healthy individuals (age: 21.3 ± 0.5 y) (6 men, 5 women). METHODS Participants trained three times a week for eight weeks performing a PC program consisting of 30 bouts of 4-s at an all-out intensity (i.e., 2 minutes of exercise per session). The cardiovascular stress progressively increased over the weeks by decreasing the recovery time between sprints (30 to 24 to 15-s) and thus total session time decreased from 17 to <10 min. RESULTS PC elicited a 13.2% increase in VO2peak (Pre: 2.86 ± 0.18 L/min, Post: 3.24 ± 0.21 L/min, (p = 0.003) and a 7.6% increase in total blood volume (Pre: 5,139 ± 199 ml, Post: 5,529 ± 342 ml, p < 0.05). Concurrently, maximal anaerobic power increased by 17.2% (Pre: 860 ± 53 watts, Post: 1,009 ± 71 watts; p < 0.001). CONCLUSION A Power Cycling training program employing 30 bouts of 4-s duration for a total of 2 min of exercise, resulting in a total session time of less than 10 min in the last weeks, is effective for improving total blood volume, VO2peak and maximal anaerobic power in young healthy individuals over 8 weeks. These observations require reconsideration of the minimal amount of exercise needed to significantly increase both maximal aerobic and anaerobic power.