Morning versus evening mat Pilates and adaptations in sleep, neuromuscular performance, and health-related quality of life in adult women: a randomized controlled trial

Whether Pilates timing influences adaptations remains unclear. This exploratory randomized controlled trial compared morning and evening mat Pilates in healthy women. Twenty-four women (41.8 ± 5.1 years) were randomized to morning (09:00–10:00), evening (19:00–20:00), or control groups (n = 8 each). The 8-week program comprised two supervised weekly sessions. The protocol was registered on OSF (https://osf.io/zur3x/). Sleep quality was primary; flexibility, strength, balance, self-esteem, and SF-36 outcomes were secondary/exploratory. False discovery rate correction was applied. PSQI scores improved over time without between-group differences (p = 0.296, q = 0.377). Leg-back strength showed an exploratory time-of-day-specific adaptation (group × time × time-of-day: F2,21 = 18.12, p < 0.001, ηp2 = 0.63, 95% CI 0.30–0.75, q < 0.001), with greatest gains at each group’s training hour. Both groups improved Spiegel scores versus controls (p = 0.008, q = 0.022). Several SF-36 domains improved; Y-Balance reach differed between groups, without clear morning-evening differences. Exercise timing influenced strength adaptation exploratorily. For other outcomes, morning-evening differences were not detectable, which does not establish equivalence. Larger trials are required before scheduling recommendations.