Effects of intensity and frequency of walking exercise on improving sleep quality in older adults with chronic insomnia: A pilot study.

Abstract

INTRODUCTION: Insomnia is a common health problem worldwide. Exercise is considered an alternative non-pharmacological aid for managing insomnia, yet how exercise frequency and intensity affect the efficacy of alleviating insomnia remains largely unclear. The purpose of this study was to compare the effects of intensity and frequency of walking exercise on improving sleep in older adults with chronic insomnia. METHODS: Thirty-one older adults (aged=> 50) with diagnosed chronic insomnia according to the DSM-V criteria, were recruited in this assessorblinded randomized controlled trial. Participants were randomly assigned to either the attention control group, who attended one weekly 75 minutes session of stretching exercise for 12 weeks (CON, n=75), or one of the four walking exercise groups with the following 12-week training regimens: 1) three sessions of moderate-intensity walking exercise (MOD×3/wk, n=6), 2) three sessions of vigorous-intensity walking exercise (VIG×3/wk, n=6), 3) one session of moderate-intensity walking exercise (MOD×1/wk, n=6), and 4) one session of vigorousintensity walking exercise (VIG×1/wk, n=6). The exercise volume of all walking exercise groups was matched. Outcome measures were conducted before and after the 12-week intervention. Pittsburgh Sleep Quality Index (PSQI) was used to assess the sleep quality and Insomnia Severity Index (ISI) was used to evaluate the insomnia severity. A lower score PSQI and ISI scores correspond to better sleep quality and lower insomnia severity respectively. RESULTS: Improvements in sleep quality were significantly larger in all exercise groups compared with CON (CON vs all exercise groups: p<0.05). Only groups with regular exercise patterns significantly alleviated the severity of insomnia (CON vs MOD×3/wk and VIG×3/wk, p<0.05). CONCLUSION: Our results showed that either exercise in small bouts across the week or performed all the recommended exercise volume on a single day weekly improves sleep quality in older insomniacs. However, higher exercise frequency may be required to induce beneficial adaptation on alleviating the severity of insomnia.