Effects of Exercise Timing and Physical Activity Level on Sleep Quality and Body Temperature

Modern lifestyles are marked by a prevalence of sedentary behaviors and physical inactivity, which have been linked to numerous adverse health effects. While regular physical exercise is a well-established countermeasure, exercising in the late afternoon may paradoxically disrupt deep sleep due to increased core body temperature. Inactive and sedentary individuals, who often have impaired autonomic function compared to endurance-trained athletes, may be particularly susceptible to these negative effects, potentially resulting in compromised thermoregulation and exacerbated disruptions to deep sleep, a critical stage of sleep essential for overall recovery. Therefore, this study aims to investigate the impact of aerobic exercise performed in the late afternoon versus morning on: 1) deep sleep and sleep onset latency; and 2) core body temperature and its autonomic regulatory mechanisms on endurance-trained and inactive-sedentary people.