They did. In fact, the relationships between moving and dozing turned out to be consistent and strong. In essence, the more steps people accumulated over the course of the month, the higher their self-rated sleep quality was during that time. Ditto when the researchers looked at the number of minutes they had spent moving; the more time someone was in motion during the month, the better they rated their sleep over all.
The linkages held even when the researchers drilled down to individual days. On any given day when someone had taken more steps than was typical for him or her, he or she usually reported better sleep quality that night. (There were few noticeable effects on sleep duration, since most of the volunteers already were sleeping about eight hours a night when the study began.)
“I think it’s fair to say” that these results indicate that people who move more also sleep better, says Alycia Sullivan Bisson, a graduate student in psychology at Brandeis, who conducted the new study with her adviser, Margie Lachman, and others.
And the activity required to see higher sleep quality was not daunting, she adds. The average step count among the 59 volunteers was about 3,000 per day, which is about a mile and a half of walking. Covering greater ground was associated with better sleep, but even among the least active, upping their mileage a bit on some days was related to better sleep later.
Of course, the links here between stepping and sleep are only links; this kind of observational study cannot prove that more walking causes better sleep. The experiment also was short-term, relied on people’s self-perceptions of how they slept, and was not set up to determine how, physiologically, walking affects the body and mind in ways that could later alter sleep.
But even with those caveats, those of us hoping for better shut-eye tonight, tomorrow and in the future might want to “incorporate more activity into our daily lives,” Ms. Sullivan Bisson says.