Associations of physical fitness and physical activity with sleep among middle-aged women.

Background: Sleep is an important component of health. Sleep disturbances increase in women as they enter menopause. Physical activity has been associated with improved sleep among older populations. The purpose of this study was to determine if physical activity and/or physical fitness are associated with sleep quantity and quality in middle-aged women.

Methods: This study recruited 114 healthy women, aged 30-55 (43±8 y) from Saskatoon, Saskatchewan, from 2015-2019. Sleep quantity and quality were evaluated. Participants were classified on their aerobic fitness, based on estimated peak aerobic capacity, as high or low grip strength and, as active or inactive.

Results: The high aerobic fitness group had a greater mean sleep duration of 7.04±1.02 h compared to the low fit group 6.61±1.00 h after adjusting for age, Body Mass Index, waist circumference and menstrual status (P=0.01). The percentage of high aerobic fitness women who felt rested was greater than low aerobic fitness women (67±6% vs. 45±7%, P=0.03), after adjusting for age, Body Mass Index, waist circumference and menstrual status. Our study found a significant difference between women with higher aerobic fitness levels getting more sleep each night and feeling more rested.

Conclusions: The continued examination of physical fitness and its relationship to sleep holds importance for women's health.