#EveningWorkouts

A sleep expert warns that exercising late in the day may undermine rest, prompting fresh questions about the best workout timing for health. In discussions with a major UK tabloid, the expert notes that while exercise is essential, finishing workouts too close to bedtime can keep the body and mind activated, making it harder to drift into deep, restorative sleep. For Thai readers, balancing a busy schedule with effective workouts is a familiar challenge, especially when after-dark training seems the only feasible option.

A new warning from sleep specialist Dr. Leah Kaylor is sparking fresh debate about the best time of day to exercise, as emerging research shows working out in the evening could disrupt the quality of your sleep. Dr. Kaylor, speaking to the Daily Mail, highlighted that while exercise is essential for health, exercising too close to bedtime can keep both body and mind too “activated” for restful sleep, leaving many fitness enthusiasts wide awake when they should be drifting off (source: Daily Mail).

A growing body of research is challenging the idea that any time is good for a workout. In particular, late-evening and nighttime exercise—especially when vigorous—may affect how well you sleep and influence markers of heart health. As urban Thais increasingly flock to parks and 24-hour gyms in Bangkok and other cities, understanding exercise timing has practical implications for daily well-being.

Many people in Thai cities juggle work, traffic, and social life, often fitting workouts after office hours. Evening strolls near Chiang Mai’s moat and HIIT sessions after work are common sights. A comprehensive 2025 study examined biometric data from more than 14,000 physically active individuals, compiling over four million nights of sleep. It found a clear dose-response: later and more intense evening workouts tended to delay sleep onset, shorten total sleep time, reduce sleep quality, raise nighttime resting heart rate, and lower heart rate variability. The effect persisted even among those who were physically fit, particularly when exercise ended within four hours of bedtime, according to research summarized by major outlets and peer-reviewed studies.

A new wave of scientific studies is challenging the popular belief that exercise at any time can boost well-being, highlighting a crucial factor for night-owl fitness enthusiasts: the clock. Recent research reported by Fortune see the article and corroborated by peer-reviewed studies has found that evening and nighttime workouts—especially when intense—may not only disrupt your sleep quality but also influence key markers of cardiovascular health. As health-conscious Thais flock to recreational parks and 24-hour fitness centers across Bangkok and major cities, the emerging science on exercise timing carries practical significance for millions striving for both physical and mental well-being.