The effects of exercise time-of-day on sleep quality and quantity among inactive middle-aged men

Penelope Larsen, Francesco Marino, Kerri Melehan, Kym J Guelfi, Rob Duffield, Melissa Skein

Research output: Other contribution to conferencePosterpeer-review

Abstract

Introduction: Many adults remain physically inactive, despite the benefits of exercise for sleep architecture, due to increased sedentary behaviour and time restraints. Methods to improve exercise compliance may include preferential time-of-day or engage in short-duration, high-intensity exercise. High-intensity exercise has many health benefits including weight loss and increased cardiovascular fitness, but when performed close to bedtime, it may reduce percent of rapid eye movement (REM) sleep. Adequate sleep quality and quantity may be more beneficial for the health of middle-aged adults, due to increased risk of disease with aging, rather than delaying or disrupting sleep to engage in exercise. Hence, the aim of this study was to investigate the effect of exercise time-of-day in middle-aged men on sleep architecture. Methods: 11 inactive men (age = 49±4.6y) completed 3 exercise trials of high-intensity interval cycling in a randomised order (60s at 100% VO2peak: 240s at 50% VO2peak) in the morning (MORN; 0600-0700h), afternoon (AFT; 1400-1600h), and evening (EVEN; 1900-2000h). Participants were screened for sleep conditions using questionnaires and 2 nights type 2 polysomnography (PSG) and the sleep studies were further used to determine baseline sleep parameters. Participants’ sleep was monitored using PSG the night following each exercise trial and scored for time in bed, total sleep time, sleep efficiency, sleep onset latency, REM onset latency, wake after sleep onset, and sleep stages (N1, N2, N3, and REM) for the whole night and first 180min after sleep onset. Results: Percent N3 sleep was greater following the MORN trial (22.9±7.3%) compared to baseline (18.0±7.2%) (p=0.02) with no other sleep-related differences. For the first 180min of sleep, percent of NREM sleep (92.4±5.1%) was greater and REM sleep (7.7±5.1%) was reduced following the EVEN trial compared to baseline (87.3±5.4%) (p=0.01). Conclusion: Sleep quantity does not appear to be influenced by high-intensity exercise regardless of exercise time-of-day. However, when high-intensity exercise is performed close to bedtime, sleep quality is reduced in the first 3h, as indicated by decreased time spent in REM sleep and incomplete sleep cycles. Also, sleep diaries indicated decreased perceived sleep quality after evening exercise compared to baseline (no exercise), morning and afternoon exercise.
Original languageEnglish
Publication statusPublished - 2017
EventAustralasian Sleep Association's (ASA) Sleep DownUnder 2017 - Auckland, New Zealand
Duration: 25 Oct 2017 → …

Conference

ConferenceAustralasian Sleep Association's (ASA) Sleep DownUnder 2017
Country/TerritoryNew Zealand
CityAuckland
Period25/10/17 → …

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