<b>The Effect of Exercise on Sleep – A Literature Review</b>

Background: Sleep is essential for physical recovery, cognitive function, emotional regulation, and cardiometabolic health. Poor sleep quality and insufficient sleep are increasingly common and are associated with sedentary behavior, stress, obesity, chronic disease, and impaired wellbeing. Exercise is a promising non-pharmacological strategy for improving sleep, but evidence varies by exercise type, intensity, timing, and population. Objective: This narrative review aimed to synthesize evidence on the effects of exercise on sleep quality, sleep duration, sleep onset, sleep architecture, and sleep-related symptoms across healthy and clinical populations. Methods: A narrative literature review was conducted using studies examining physical activity, aerobic exercise, resistance training, aquatic exercise, Nordic walking, yoga, Tai Chi, Baduanjin, and combined exercise programs in relation to sleep outcomes. Evidence was synthesized thematically according to exercise modality, population characteristics, physiological mechanisms, and sleep-related outcomes. No meta-analysis was performed because of heterogeneity in study designs, interventions, and outcome measures. Results: The reviewed evidence suggests that regular exercise is generally associated with improved sleep quality, longer sleep duration, reduced sleep latency, and favorable changes in sleep architecture. Aerobic and endurance exercise improved sleep continuity, resistance training enhanced subjective sleep quality, and aquatic and mind-body exercises appeared beneficial for older adults and individuals with physical limitations. Exercise also showed positive effects in anxiety patients, breast cancer patients, overweight or obese individuals, and people undergoing tobacco withdrawal. Conclusion: Exercise is a safe and clinically relevant non-pharmacological approach for improving sleep. However, further controlled studies are needed to define optimal exercise type, timing, intensity, and dose for specific populations.