High-intensity interval exercise induces greater acute changes in sleep, appetite-related hormones, and free-living energy intake than does moderate-intensity continuous exercise.

The aim of this study was to compare the effect of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) on sleep characteristics, appetite-related hormones, and eating behaviour. Eleven overweight, inactive men completed 2 consecutive nights of sleep assessments to determine baseline (BASE) sleep stages and arousals recorded by polysomnography (PSG). On separate afternoons (1400-1600 h), participants completed a 30-min exercise bout: either () MICE (60% peak oxygen consumption) or () HIIE (60 s of work at 100% peak oxygen consumption: 240 s of rest at 50% peak oxygen consumption), in a randomised order. Measures included appetite-related hormones (acylated ghrelin, leptin, and peptide tyrosine tyrosine) and glucose before exercise, 30 min after exercise, and the next morning after exercise; PSG sleep stages; and actigraphy (sleep quantity and quality); in addition, self-reported sleep and food diaries were recorded until 48 h after exercise. There were no between-trial differences for time in bed ( = 0.19) or total sleep time ( = 0.99). After HIIE, stage N3 sleep was greater (21% ± 7%) compared with BASE (18% ± 7%; = 0.02). In addition, the number of arousals during rapid eye movement sleep were lower after HIIE (7 ± 5) compared with BASE (11 ± 7; = 0.05). Wake after sleep onset was lower following MICE (41 min) compared with BASE (56 min; = 0.02). Acylated ghrelin was lower and glucose was higher at 30 min after HIIE when compared with MICE ( ≤ 0.05). There were no significant differences between conditions in terms of total energy intake ( ≥ 0.05). HIIE appears to be more beneficial than MICE for improving sleep quality and inducing favourable transient changes in appetite-related hormones in overweight, inactive men. However, energy intake was not altered regardless of exercise intensity.