Sleep and exercise relation

Sleep and exercise influence each other in both directions:

• Exercise can improve sleep: Physical activity during the day tends to boost sleep quality, especially deep slow-wave sleep. High-intensity exercise may modestly shift sleep toward more deep sleep and less REM, though sleep stages naturally vary. 1
• Timing matters: Intense exercise close to bedtime can make sleep harder for some people; earlier exercise is more likely to support sleep. If evening training is unavoidable, allow time to wind down afterward. 2 3
• Sleep supports exercise performance and safety: Too little sleep can reduce physical performance and motivation to exercise, and raise injury risk. 4
• After one poor night: Moderate, careful exercise may help offset some negative effects on brain performance; avoid overly intense or injury-prone activity, and don’t use exercise as a substitute for adequate sleep. 5