Early Bedtimes May Boost Physical Activity: Study Finds - Video

Going to bed earlier than usual could lead to more physical activity the next day, according to a new study led by Monash University and published in Proceedings of the National Academy of Sciences (PNAS). The research examined how both habitual and nightly variations in sleep timing and duration relate to next-day physical activity, offering important insights for public health strategies.

The primary study involved nearly 20,000 participants who wore WHOOP biometric devices for one year, generating almost six million nights of data. These wrist-worn devices provided objective, real-time measurements of both sleep and physical activity.

Results showed that earlier bedtimes were consistently associated with higher levels of physical activity. For instance, individuals who typically went to bed around 9pm engaged in approximately 30 more minutes of moderate-to-vigorous physical activity each day compared to those who stayed up until 1am. Even compared to the study average of 11pm, those with 9pm bedtimes logged nearly 15 extra minutes of activity.

Lead author Dr Josh Leota from Monash University’s School of Psychological Sciences noted that this pattern may be particularly relevant for people whose natural sleep preferences conflict with standard work hours. “Standard 9-to-5 routines can clash with the natural sleep preferences of evening types, leading to social jetlag, poorer sleep quality, and increased daytime sleepiness – which can all reduce motivation and opportunity for physical activity the next day,” Dr Leota said.

Importantly, the study found that when individuals went to bed earlier than usual without reducing their overall sleep duration—they recorded the highest levels of next-day physical activity. “These insights carry meaningful implications for public health,” Dr Leota added. “A holistic approach that recognises how these two essential behaviours interact may lead to better outcomes for individual and community health.”

The findings suggest that encouraging earlier bedtimes could be a simple yet effective strategy to promote healthier, more active lifestyles.

Reference: J. Leota, M.É. Czeisler, F. Le, D.M. Presby, E.R. Capodilupo, H. Scott, J.F. Wiley, S.P.A. Drummond, S.M.W. Rajaratnam, & E.R. Facer-Childs, Sleep duration and timing are associated with next-day physical activity: Insights from two large-scale wearable sensor studies, Proc. Natl. Acad. Sci. U.S.A. 122 (27) e2420846122, https://doi.org/10.1073/pnas.2420846122 (2025).