Prior Exercise and Circulorespiratory Endurance

Abstract Subjects (N = 12) performed a circulorespiratory endurance task 2 min. after completing 10 min. of exercise at each of four intensities of prior exercise (PE). The PE was adjusted to maintain heart rate (HR) at resting levels (no exercise), 110, 140, and 170 bpm. The criterion task required the subject to pedal against a resistance of 3 kg. at a starting rate of 68 rpm. As he tired and could not maintain the pace, he kept going as fast as possible. His score was the number of revolutions for each minute of the 10-min. task. For the sixth minute of the task, performance following the PE at HR 170 was significantly worse (P < .05) than that following rest, 110 and 140 bpm, while the latter three treatments did not differ significantly. For the rest, 140 and 170 treatments there was a significant tendency for the subjects to slow down from minute 1-6 and then to speed up from minutes 8-10. The slight deterioration in performance following PE at 170 bpm was attributed to possible lactate accumulation...