Exercise as a therapeutic strategy for insomnia: Current mechanisms and clinical relevance.

Insomnia affects 10-30 % of adults, with higher prevalence among older individuals, women, and those with comorbid medical or psychiatric conditions. It disrupts cognitive function, emotional regulation, and physical health, elevating risks for depression, cardiovascular disease, and diminished quality of life. Although pharmacological treatments have offered short-term symptom relief, their use has been constrained by side effects, dependency potential, and limited long-term efficacy, underscoring the need for effective non-pharmacological alternatives. Exercise has emerged as a well-supported, low-risk intervention, with moderate-intensity aerobic exercise, resistance training, and mind-body modalities (e.g., yoga, tai chi) demonstrating consistent benefits in sleep improvement. These interventions have been found to reduce sleep onset latency (SOL), increase total sleep time (TST), enhance sleep efficiency (SE), and improve subjective sleep satisfaction, as measured by validated tools such as the Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI). Objective assessments via polysomnography (PSG) and actigraphy have corroborated these findings, showing decreased wake after sleep onset (WASO) and increased slow-wave sleep (SWS). Mechanistically, exercise has been shown to modulate the hypothalamic-pituitary-adrenal (HPA) axis, elevate brain-derived neurotrophic factor (BDNF), regulate circadian rhythms, attenuate systemic inflammation, and increase availability of sleep-related neurotransmitters. Multiple randomized controlled trials have confirmed that moderate-intensity exercise significantly improves sleep parameters, supporting its incorporation into insomnia treatment frameworks. Nonetheless, further large-scale, rigorously designed studies are needed to refine exercise protocols and clarify population-specific responses. This review aimed to elucidate the physiological mechanisms underlying exercise-induced sleep improvements and assess its potential as a sustainable, low-risk alternative to pharmacotherapy in insomnia management.