Oxygen consumption, rate of perceived exertion and enjoyment in high-intensity interval eccentric cycling

The objectives of this article are to compare oxygen consumption (VO2) and perceptual responses between continuous and interval eccentric cycling protocols in order to test the hypothesis that metabolic demand and enjoyment would be greater for interval than continuous eccentric cycling protocols. Eleven recreationally active men (n=9) and women (32.6 +/- 9.4 years) performed a concentric cycling test to determine peak power output (PPO) followed by five eccentric cycling protocols on separate occasions: continuous eccentric cycling at 60% of PPO for 20min at 60rpm (CONT20@60%) and 13.2min at 90rpm (CONT13@60%), 4x4min at 75% of PPO with 2-min rest (INT4x4@75%), 12x1min at 100% of PPO with 1-min rest (INT1x12@100%) and 10x1min at 150% of PPO with 1-min rest (INT1x10@150%). Gas exchange and power output were recorded continuously, and rate of perceived exertion (RPE) and enjoyment were assessed after each exercise. Total VO2 including the rest periods was the greatest (p<0.0001) during INT1x10@150% (382 +/- 73mlkg(-1)) and lowest (p<0.0001) during CONT13@60% (146 +/- 27mlkg(-1)). Total VO2 during INT1x12@100% (312 +/- 59mlkg(-1)) was greater (p<0.0001) than CONT20@60% (246 +/- 63mlkg(-1)) and INT4x4@75% (257 +/- 42mlkg(-1)). RPE was greater (p<0.0001) after INT1x10@150% (17 +/- 2) than other conditions, but perceived enjoyment was not significantly different between protocols. It was concluded that the interval protocols increased metabolic demand without increasing RPE and enjoyment. It appears that high-intensity interval protocols can be used in eccentric cycling prescription.