In the United States, as much as 1 in 3 adults do not get enough quality sleep. It is estimated that nine million adults rely on medication to help them fall asleep regularly, although recent evidence has highlighted side effects such as dependency on sleep aides, cancer and possible even death.
While previous longitudinal studies have shown a strong correlation between sleep and exercise, this article specifically investigated the daily changes in physical activity and their effects on sleep.
When examined over a month, increased activity levels were related to improvements in overall sleep quality, but not sleep duration. It was found that women experienced greater benefits from bouts of acute activity. On a daily basis, increased exercise improved that same day’s sleep quality.
It is speculated that improved sleep quality is probably more important (and easier) to obtain through physical activity than increased sleep duration, as other factors such as schedule conflicts and outside responsibilities (such as with work and family) may make it harder for people to increase their sleep duration with increased physical activity alone.
> From: Sullivan Bisson et al., Sleep Health 5 (2019) 487-494 . All rights reserved to National Sleep Foundation. Click here for the online summary.
This article highlights the important role between physical activity and sleep, and utilised a common activity tracker to investigate this, which makes the ecological validity of this study very high, i.e. achievable for a large population. Moreover, the researchers also set a realistic walking goal, and found a positive correlation between sleep and activity, particularly in women.
However, this study did have some limitations: there was a disproportionate number of female participants, and the self-reported questionnaires for sleep quality and sleep duration were not described in detail. A standardised outcome measure, as well as using other technology (such as a sleep monitor, for instance) could have led to other or at least more detailed outcomes than just self-reporting.
All this aside, this article does make a compelling case for the importance of exercise for sleeping well, especially with the growing number of people worldwide who struggle with this each night.