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

Compare the effect of high-intensity interval and moderate-intensity continuous exercise on sleep characteristics, appetite-related hormones and eating behaviour. 11 overweight, inactive men completed two consecutive nights of sleep assessments to determine baseline (BASE) sleep stages and arousals recorded by polysomnography (PSG). On separate afternoons (1400-1600h), participants completed a 30min exercise bout: 1) moderate-intensity continuous exercise (MICE; 60% V̇O2peak) or 2) high-intensity interval exercise (HIIE; 60s work at 100% V̇O2peak: 240s rest at 50% V̇O2peak), in a randomised order. Measures included appetite-related hormones (acylated ghrelin, leptin, peptide tyrosine tyrosine) and glucose pre-exercise, 30min post-exercise, and the next morning post-exercise; PSG sleep stages, actigraphy (sleep quantity and quality), and self-reported sleep and food diaries were recorded until 48h post-exercise. There was no between-trial differences for time in bed (p=0.19) or total sleep time (p=0.99). For HIIE, stage N3 sleep was greater (21 ± 7%) compared to BASE (18 ± 7%; p=0.02). Also, number of arousals during rapid eye movement sleep were lower for HIIE (7 ± 5) compared to BASE (11 ± 7; p=0.05). Wake after sleep onset was lower following MICE (41min) compared to BASE (56min; p=0.02). Acylated ghrelin was lower and glucose higher at 30min post-exercise for HIIE compared to MICE (p≤0.05). There were no significant differences in total energy intake between conditions (p≥0.05). HIIE appears 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.