Reliability of power output during intermittent high-intensity cycling.

Abstract

We determined the number of trials on consecutive days required to establish high reliability of an intermittent high-intensity cycling test in subjects unfamiliar with multiple-sprint exercise. We also examined the extent to which this reliability could be maintained for 6 d. Five untrained men performed a multiple-sprint test (10 x 7 s, with each sprint separated by 30 s) on each of four consecutive days (days 1-4), then rested for 6 d, and finally performed two additional tests on consecutive days (days 11 and 12). For statistical comparisons (analyses of variance), mean power outputs during sprints 8, 9, and 10 (MP8-10) on each test day were calculated for each of the 4th, 5th, and 6th seconds of the sprints, i.e., MP8-10(4th), MP8-10(5th), and MP8-10(6th). Peak power during each sprint was also examined. For days 3 and 4, values for MP8-10(4th), MP8-10(5th), and MP8-10(6th) were greater than on day 1 (P < 0.05). MP8-10(6th) on day 2 was also greater than on day 1 (P < 0.05). There were no differences in MP8-10 among days 2, 3, 4, 11, and 12. Also, peak power on day 1 was lower (P < 0.05) than peak power for all other days, which were not different from one another. The coefficients of variation (CV) for MP8-10 on day 3 versus day 4 were 3.3%, 2.5%, and 2.9% for MP8-10(4th), MP8-10(5th), and MP8-10(6th), respectively. The CV for MP8-10(4th), MP8-10(5th), and MP8-10(6th) on days 4, 11, and 12 ranged from 2.1 to 3.9%, with an overall mean of 3.1%. The greatest CV for MP8-10 was 5.2% for MP8-10(6th) on days 2 versus 3 and 2 versus 4. The mean CV for peak power for all pairwise combinations of days 4, 11, and 12 was 2.8%. In conclusion, satisfactory reliability of intermittent cycling tests is achieved after two familiarization sessions identical to the tests, and that reliability can be maintained for 6 d.