Exercise before bed does not impact sleep inertia in young healthy males

Abstract

Sleep inertia is the transitional state marked by impaired cognitive performance and reduced vigilance upon waking. Exercising before bed may increase the amount of slow‐wave sleep within the sleep period, which has previously been associated with increased sleep inertia. Healthy males (n = 12) spent 3 nights in a sleep laboratory (1‐night washout period between each night) and completed one of the three conditions on each visit – no exercise, aerobic exercise (30 min cycling at 75% heart rate), and resistance exercise (six resistance exercises, three sets of 10 repetitions). The exercise conditions were completed 90 min prior to bed. Sleep was measured using polysomnography. Upon waking, participants completed five test batteries every 15 min, including the Karolinska Sleepiness Scale, a Psychomotor Vigilance Task, and the Spatial Configuration Task. Two separate linear mixed‐effects models were used to assess: (a) the impact of condition; and (b) the amount of slow‐wave sleep, on sleep inertia. There were no significant differences in sleep inertia between conditions, likely as a result of the similar sleep amount, sleep structure and time of awakening between conditions. The amount of slow‐wave sleep impacted fastest 10% reciprocal reaction time on the Psychomotor Vigilance Task only, whereby more slow‐wave sleep improved performance; however, the magnitude of this relationship was small. Results from this study suggest that exercise performed 90 min before bed does not negatively impact on sleep inertia. Future studies should investigate the impact of exercise intensity, duration and timing on sleep and subsequent sleep inertia.

To Nap or Not to Nap? A Systematic Review Evaluating Napping Behavior in Athletes and the Impact on Various Measures of Athletic Performance

“…A recent study by our team investigated the possibility whether athletes exercising prior to their night-time sleep periods would exhibit greater amounts of slow-wave sleep in their night-time sleep period, which could subsequently impact the severity and/or duration of sleep inertia. 98 This hypothesis could potentially mean that athletes may be more susceptible to the impacts of sleep inertia given (in most cases) that their level of exercise is greater than the general population. 98 However, this study concluded that exercise of a moderate-intensity performed 90 min before bed did not negatively impact sleep inertia and there was no relationship between the amount of slow wave sleep in the preceding sleep period and sleep inertia.…”

“… 98 This hypothesis could potentially mean that athletes may be more susceptible to the impacts of sleep inertia given (in most cases) that their level of exercise is greater than the general population. 98 However, this study concluded that exercise of a moderate-intensity performed 90 min before bed did not negatively impact sleep inertia and there was no relationship between the amount of slow wave sleep in the preceding sleep period and sleep inertia. 98 Therefore, it seems unlikely that athletes have a greater likelihood of experiencing enhanced duration and/or severity of sleep inertia compared to non-athletes.…”

The effect of a short burst of exercise during the night on subsequent sleep

“…The participants refrained from exercising on study days apart from the designated exercise period. Prior to going to bed, electrodes were attached to the participants' head and face using a standard montage, reported elsewhere (Vincent et al., 2019b). At 24:00 hours lights were turned off and participants went to sleep.…”

“…Participants were required to have habitual bedtimes and wake times within 2 hr of the study bedtimes and wake times (bedtimes between 22:00 and 24:00 hours and wake times between 06:00 and 09:00 hours). These are common exclusion criteria for sleep or exercise studies because they are known confounds for sleep or exercise interventions (Kovac, Vincent et al, 2020b;Vincent et al, 2019aVincent et al, , 2019b. During the recruitment process, 21 out of 41 participants did not satisfy the exclusion criteria and were excluded.…”

Examining the Role of Exercise Timing in Weight Management: A Review

“…Together, these data suggest that the sleep quality benefits of chronic exercise training may be more related to consistently performing exercise rather than the time of the exercise bout. Notably, the majority of sleep and exercise research has been conducted in healthy young men, many of whom are highly trained athletes [97][98][99][100][101][102][103]. Therefore, a major gap in the current literature is a lack of studies in populations that are translatable to the overall population.…”