The University of Saskatchewan’s (USask) Dr. Heather Foulds (PhD) and her team of students have conducted a new study which confirms a significant difference between women with higher aerobic fitness levels getting more sleep each night and feeling more rested.

Although this study was conducted prior to the pandemic, Foulds believes this research is still applicable to women experiencing the pandemic. “There’s more underlying stress and more challenges,” said Foulds, an assistant professor in the College of Kinesiology who specialises in Indigenous health and cardiovascular health, and the Heart & Stroke/CIHR Indigenous Early Career Women’s Heart and Brain Health Chair at USask.

Sleep plays an important role in our health, and as women enter menopause they could experience a further decrease in their sleep quality.

Physical activity has been associated with improved sleep among older people.

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.

The study recruited 114 healthy women, aged 30-55 from Saskatoon, Saskatchewan, from 2015-2019. Participants were classified on their aerobic fitness, grip strength and how physically active they were. The aerobic fitness test was based on walking, with participants being asked to walk as far as they could and as fast as they could in six minutes. It was noted that women who were more fit could walk farther and were able to keep a higher speed.

Next was grip strength to test musculoskeletal fitness. Participants were asked to hold a device in their hand and squeeze it as tightly as they were able. The device measured how many kilograms each participant was able to squeeze. This was done on both hands to get an overall total for their grip strength.

Participants also filled out a questionnaire to measure their level of physical activity. The results from each test helped divide the participants into two classifications – those who were more fit and those who weren’t, which provided a more accurate representation of the relationship between each participant’s fitness level and their sleep experience.

Both sleep quantity and quality were evaluated through questionnaires. Sleep quantity was measured by noting the number of hours slept, and sleep quality was measured through the answers to questions such as ability to fall asleep, staying asleep, waking up earlier than intended, and if they felt restful when waking up or tired and fatigued.

From thinking about which activities are possible to do safely and won’t put your family’s health at risk, to juggling responsibilities between working from home and looking after their children, the pandemic was also relevant to the study “All of these things can contribute to a lack of sleep,” said Foulds.

However overall, the study showed that women who are more physically active and have a higher aerobic fitness level tend to have better sleep.

The high aerobic fitness group had a greater mean sleep duration of 7.04 hours compared to the low fit group of 6.61 hours after adjusting for age, Body Mass Index, waist circumference and menstrual status.

The percentage of high aerobic fitness women who felt rested was calculated at 67 percent compared to low aerobic fitness women 45 percent.