Razi University

Background and Purpose: Poor sleep quality may be associated with impaired physical and psychological recovery, reduced daily functioning, and greater fatigue. Exercise is considered a practical non-pharmacological strategy for supporting sleep health; however, evidence regarding the acute differences between aerobic and resistance exercise remains limited and inconsistent, particularly in inactive individuals with poor sleep quality. Therefore, the present study aimed to compare the acute effects of a single session of aerobic exercise and a single session of resistance exercise on sleep-related indices in inactive men with poor sleep quality. Methods: This study used a randomized crossover design with counterbalancing and included 30 inactive men aged 20–44 years who were overweight and had poor sleep quality. Each participant completed both the aerobic and resistance exercise conditions, separated by a one-week interval. The aerobic session consisted of 30 minutes of brisk walking or light jogging at 60–70% of maximal heart rate. The resistance session included eight exercises targeting the major muscle groups, performed for two sets of 10–12 repetitions at approximately 60% of one-repetition maximum. Both sessions were performed in the evening and at least three hours before the participants’ usual bedtime. Sleep quality, ease of getting to sleep, ease of awakening, and perceived recovery after awakening were assessed the following morning using the Leeds Sleep Evaluation Questionnaire. Pre-sleep sleepiness was assessed using the Karolinska Sleepiness Scale, while morning mood and fatigue were evaluated using the short form of the Profile of Mood States. The two exercise conditions were compared using the paired-samples t-test, with statistical significance set at 0.05. Results: Sleep quality was significantly more favorable after aerobic exercise than after resistance exercise (p=0.013). Ease of getting to sleep was also significantly more favorable following aerobic exercise (p=0.008). No significant differences were observed between the two conditions in ease of awakening (p=0.340), perceived recovery after awakening (p=0.069), pre-sleep sleepiness (p=0.083), or mood the following morning (p=0.382). Morning fatigue was significantly lower after aerobic exercise than after resistance exercise (p=0.024). Conclusion: The findings indicate that, in inactive overweight men with poor sleep quality, a single session of moderate-intensity aerobic exercise was associated with more favorable sleep quality, greater ease of getting to sleep, and lower fatigue the following morning compared with a single session of moderate-intensity resistance exercise. However, the two exercise modes did not differ significantly in the other outcomes examined. These findings suggest that the acute effects of exercise mode may differ across specific dimensions of sleep and next-morning recovery rather than across all sleep-related outcomes.