Abstract P199: Improvements in Sleep Quality Following Moderate, but Not Light-Intensity Acute Aerobic Exercise in Older Women
Introduction: Sleep has profound effects on metabolism and health outcomes with poor sleep quality being associated with adverse outcomes. Less is known whether exercise can improve sleep quality and whether intensity of the exercise affects any effects on sleep.
Hypothesis: We hypothesized that a single aerobic exercise session would improve sleep quality in older women.
Methods: Fifteen healthy, non-obese (body mass index = 24.4 ± 2.1 kg/m2, mean ± SD), sedentary (<20 min of exercise on no more than 3 times/week) older women (66.1 ± 3.9 years) volunteered for the study. Peak oxygen consumption (VO2peak) was evaluated using a graded exercise test on a treadmill with a metabolic cart. Following a 7-day baseline period, each participant completed two exercise sessions (separated by 1 week) with equal caloric expenditure (3.5 kcal/kg body weight), but at different intensities (60% and 45% VO2peak, sequence randomized) between 9-11am. A wrist ActiGraph monitor was used to assess sleep at baseline and two nights following each exercise session.
Results: The average duration of the exercise was 54 and 72 min, respectively at 60% (moderate-intensity) and 45% VO2peak (light-intensity). The total sleep time was not different at baseline, after light- and moderate-intensity exercise (489 ± 55, 455 ± 87, and 443 ± 84 min, respectively). Total activity counts after sleep onset were significantly lower during the nights after the moderate-intensity exercise than at baseline (2.5k ± 1.3k and 3.6k ± 1.9k, respectively, p = 0.05); the number of awakenings after sleep onset was also significantly lower (12.9 ± 6.2 and 15.9 ± 8.4, respectively, p = 0.046). Total activity counts (2.8k ± 1.7k) and the number of awakenings (14.7 ± 9.5) after sleep onset during the nights after the light-intensity exercise were non-significantly lower than at baseline and non-significantly higher than after the moderate-intensity exercise.
Conclusion: Our data suggest that a single moderate-intensity aerobic exercise session improved sleep quality greater than an exercise session at a light-intensity in older women.
- © 2013 by American Heart Association, Inc.