LAUSR

HIGHLIGHTS Adults are recommended to engage in moderate-vigorous physical activity (MVPA) to maintain health. But including exercise sessions within a day inevitably requires reallocating time from other physical behavior(s): sleep, sedentary behavior, or physical activity.We studied the time reallocations induced by 65 min/day of morning exercise (cycling MVPA) in physically active participants.Participants spent less time sleeping and higher time on total (including exercise) MVPA on days that included exercise compared to days without exercise. Thus, participants reallocated sleep time to accommodate morning exercise sessions.Some participants also spent higher time on sedentary behavior during days that included exercise compared to days without exercise. This probably represents a behavioral compensatory response to exercise-induced fatigue.Together, time reallocations and behavioral compensatory responses led to a rearrangement of daily time spent on physical behaviors. This rearrangement was estimated to produce large interindividual variability in the increase in energy expenditure induced by exercise.