News Release

Fitbit user data show slight increase in sleep duration in US during COVID-19 pandemic

Data from more than 163,000 Fitbit users allow large-scale analysis of sleep variables

Peer-Reviewed Publication

American Academy of Sleep Medicine

DARIEN, IL - According to a study of data from more than 163,000 Fitbit users, sleep duration increased slightly in 2020 during the COVID-19 pandemic compared with a similar timeframe in 2019.

Results show that mean sleep duration increased in nearly all groups by 5 to 11 minutes, compared with a mean decrease of 5 to 8 minutes seen over the same period in 2019. Sleep timing shifted later for nearly all groups. Sleep duration and bedtime variability decreased, largely due to fewer differences between weekday and weekend sleep.

"The most surprising thing we found was that, overall, sleep duration increased slightly, and sleep variability decreased slightly, during the most intense months of the pandemic," said lead author Michael Grandner, who has a doctorate in clinical psychology and is the director of the sleep and health research program at the University of Arizona College of Medicine. "It was also interesting to see that the degree of change in sleep was correlated with the degree of improvement in resting heart rate."

The researchers analyzed sleep variables extracted from data contributed by 163,524 deidentified, active Fitbit users from six major U.S. cities, representing areas particularly hard-hit by the pandemic: Chicago, Houston, Los Angeles, New York, San Francisco, and Miami. Deviation from similar timeframes in 2019 were examined.

"The results provide perhaps the largest study of objective sleep recordings from a geographically diverse general population sample during the height of the pandemic," said Grandner. "They are also important because they document important population trends, such as delayed bedtime and extended sleep, perhaps due to stay-at-home orders."


The study was co-authored by Naghmeh Rezaei, who has a doctorate in physics and is a staff data scientist at Fitbit.

The research abstract was published recently in an online supplement of the journal Sleep and will be presented beginning June 9 during Virtual SLEEP 2021. SLEEP is the annual meeting of the Associated Professional Sleep Societies, a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society. The full manuscript also was published recently in the journal Sleep Health.

This research was supported by Fitbit, Inc.

For a copy of the abstract, "Longitudinal Changes in Sleep Duration, Timing, Variability, and Stages during the COVID-19 Pandemic: Large-Scale Fitbit Data," or to arrange an interview with the study author or an AASM spokesperson, please contact AASM Communications Coordinator Corinne Lederhouse at 630-737-9700, ext. 9366, or

About the American Academy of Sleep Medicine

Established in 1975, the American Academy of Sleep Medicine (AASM) is advancing sleep care and enhancing sleep health to improve lives. The AASM has a combined membership of 11,000 accredited member sleep centers and individual members, including physicians, scientists and other health care professionals (

About the Sleep Research Society

The Sleep Research Society (SRS) is a professional membership society that advances sleep and circadian science. The SRS provides forums for the exchange of information, establishes and maintains standards of reporting and classifies data in the field of sleep research, and collaborates with other organizations to foster scientific investigation on sleep and its disorders. The SRS also publishes the peer-reviewed, scientific journals Sleep and Sleep Advances (

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