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.
US Masters Swimming 1,500-m freestyle performance times with advancing age. A: mean (population) quadratic line and 95% confidence intervals. B: average quadratic line and individual regression lines. Pink identifies women, and blue identifies men.
