Short-term effect of physical activity on sleep health: A population-based study using accelerometry

Area of Science:

• Sleep Science
• Exercise Physiology
• Public Health

Background:

• Physical activity (PA) is crucial for sleep health.
• Short-term effects of PA on sleep remain debated.
• Investigating PA timing and intensity effects on sleep is important for young adults.

Purpose of the Study:

• To examine how different intensities of physical activity (PA) performed at various times of day affect subsequent sleep in young adults.
• To analyze sex-specific differences in the relationship between PA and sleep outcomes.

Main Methods:

• Prospective analysis of the 1993 Pelotas Birth Cohort (mean age 22.6 years).
• Objective measurement of PA and sleep using wrist-worn accelerometry.
• Stratified analysis by PA intensity (light, moderate, vigorous) and time of day, with sleep variables including sleep time window, total sleep time, and sleep percent.

Main Results:

• Morning light PA (LPA) increased total sleep time in men and sleep percent in women.
• Afternoon LPA also improved sleep percent in women.
• Moderate and vigorous PA in the morning/afternoon showed no significant association with sleep variables.
• PA performed at night appeared to negatively impact sleep for both sexes and all intensities.

Conclusions:

• The impact of PA on sleep health is dependent on the time of day it is performed.
• Sex differences exist in the magnitude of PA's effect on sleep.
• Daytime physical activity, particularly light activity in the morning, is recommended for improved sleep health in young adults.