Time Change and Exercise

Does daylight saving time make people more or less physically active? Researchers tackled the question

Animated graphic of three small human figures: a woman in red shorts, white sneakers and t-shirt jogging atop of a round clock that shows the numbers 10, 11, 12, 1 1 and 2. The lady jogger is followed by a male jogger in red shorts and a woman jogger in a blue warmup suit with gray hair.
Graphic courtesy of the Pratt School of Engineering at Duke University.

This is a summary of a story that originally appeared on the Pratt School of Engineering.

The beginning and end of daylight saving time (DST) comes with simple instructions in concert with the season: we either spring forward or fall back an hour.

The time change typically ignites vigorous debates and assertions in some quarters that the longer days have intrinsic benefits, while others say it poses health risks.

A Duke study published last month tackled the question: Does DST make people more, or less physically active?

The answer is neither, according to the study. The researchers found no appreciable difference in the daily number of steps taken before or after a time change.

“Overall, changing times does not seem to be the public health benefit that some think that it is, at least in terms of activity levels,” said Jessilyn Dunn, associate professor of biomedical engineering at Duke, and one of the study’s co-authors.

For the study, Dunn and Ph.D. students relied on data from the All of Us Research Program. The initiative — funded and administered by the National Institutes of Health  — serves as a clearinghouse for Fitbit data volunteered annually by more than 50,000 people from all over the country. The result is a huge database used by thousands of studies like Duke’s DST research.

The researchers focused on the “four corner” states of Arizona, Colorado, New Mexico and Utah; most of Arizona does not observe DST.

For more information about the researchers’ findings on exercise patterns visit the Duke Pratt School of Engineering.