Men, Women and Speed

Some scientists are finally admitting the obvious:

Women are slower than men in running, in swimming, in cycling. Whether it is a 100-meter race on the track or a marathon, a 200-meter butterfly swim or a 10-kilometer marathon swim, the pattern holds.

And even though some scientists once predicted that women would eventually close the gender gap in elite performances — it was proposed that all they needed was more experience, better training and stronger coaching — that idea is now largely discredited, at least for Olympic events. Researchers say there is no one physiological reason for the gap, although there is a common biological thread.

“To a large extent, it’s a matter of testosterone,” said Dr. Benjamin Levine, ...

The hormone affects everything from muscle size and strength to the size of the heart to the amount of oxygen-carrying blood cells in the body to the percentage of fat on an athlete’s body. Every one of those effects gives men a performance advantage.