Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
NA indicates not applicable; SMD, standardized mean difference.
aFor studies using accelerometers, mean values reflect minutes of moderate-to-vigorous physical activity. For studies using pedometers, mean values reflect total daily steps.
