Health Notes

Few people would be surprised to hear that physical activity improves sleep. But what may be surprising is that, according to researchers from the University of Pennsylvania, not all types of physical activity seem to improve sleep to the same extent. The researchers, who presented the results of their study at a 2015 meeting of the Associated Professional Sleep Societies LLC, looked at data for 429,110 adults from the 2013 Behaviour Risk Factor Surveillance System (BRFSS). The BRFSS is a federally sponsored phone survey programme that asks US residents questions about health-related behaviours, chronic diseases, and prevention strategies. Specifically, researchers examined the BRFSS data to look for relationships between the amount of time participants slept (more or less than seven hours per night) and ten types of physical activity: walking, aerobics/calisthenics, biking, gardening, golfing, running, weight-lifting, yoga/Pilates, household chores, and childcare-related activities. After taking into account the participants' age, sex, education level, and body mass index, the researchers discovered that:

• Compared with participants who reported no physical activity in the month prior to the survey, participants who engaged in almost any of the ten types of physical activity had better sleep outcomes, meaning they were more likely to get seven hours or more of sleep per night.
• Two types of physical activity weren't associated with better sleep outcomes: household chores and childcare-related activities.
• Those who engaged in more “purposeful” types of physical activity, such as running, yoga, gardening, or golf, had even better sleep outcomes than those who simply reported walking.

It's important to point out that the study was observational and so can't prove a cause-and-effect relationship between these specific forms of physical activity and sleep quality. For example, people who engage in more “purposeful” forms of physical activity may have other lifestyle habits that the researchers didn't take into account, such as better financial security or more balanced diets, which may also contribute to better sleep. Similarly, those who spend a lot of their time looking after children or doing housework may be more stressed, which could cancel out some of the positive effects on sleep.

Source: University of Pennsylvania School of Medicine