The impact of a short burst of exercise on sleep inertia
Publication Date
12-1-2021
Document Type
Article
Publication Title
Physiology and Behavior
Volume
242
DOI
10.1016/j.physbeh.2021.113617
Abstract
Study objectives: Determine whether 30 s (s) of exercise performed upon waking can reduce sleep inertia and accelerate an increase in the cortisol awakening response (CAR) and core body temperature (CBT), compared to when sedentary. Methods: Fifteen participants (mean age ± SD, 25.9 ± 5.9 years; six females) completed a counterbalanced, repeated measures, in-laboratory study involving three single experimental nights, each separated by a four-night recovery period. Participants were woken following a 2-h nap (2400–0200) and completed a cycling bout of high-intensity (30-s sprint), low-intensity (30 s at 60% maximum heart rate), or no exercise (sedentary). Sleep inertia testing (eight batteries, 15-min intervals) began immediately following and included measures of subjective sleepiness (Karolinska Sleepiness Scale) and cognitive performance tasks (psychomotor vigilance, serial addition and subtraction, and spatial configuration). CBT was measured continuously via an ingestible telemetric capsule. The CAR was determined using salivary cortisol samples collected at 0, 30 and 45 min post-waking. Data were analysed using mixed effects analysis of variance. Results: There was no difference in cognitive performance or CBT between conditions. Participants felt less sleepy in the high-intensity condition, followed by the low-intensity and sedentary conditions (p = .003). The CAR was greatest in the high-intensity condition, followed by the sedentary condition, and low-intensity condition (p < 0.001), with no differences between the low-intensity and sedentary conditions. Conclusions: Those who exercise upon waking should be aware that while they may feel more alert, they may not be performing better than if they had not exercised. Future research should investigate whether exercise of different duration or timing may impact sleep inertia.
Funding Number
000020701
Funding Sponsor
Central Queensland University
Keywords
Awakening, Core body temperature, Cortisol awakening response, Exercise, Sleep inertia
Department
Research Foundation
Recommended Citation
Katya Kovac, Grace E. Vincent, Jessica L. Paterson, Amy Reynolds, Brad Aisbett, Cassie J. Hilditch, and Sally A. Ferguson. "The impact of a short burst of exercise on sleep inertia" Physiology and Behavior (2021). https://doi.org/10.1016/j.physbeh.2021.113617
