One study with women showed a much bigger muscle growth difference than the others — all of which were only with men — suggesting sex might matter, but we need more studies to know for sure.

When men and women do strength training, their fast-twitch muscle fibers grow about the same amount—so sex doesn’t really make a difference in how much these muscles get bigger.

When men and women do strength training, their big, powerful muscle fibers grow about the same amount—neither sex consistently gains more muscle than the other.

Men naturally have bigger fast-twitch muscle fibers than women, even if neither exercise, showing a clear biological difference between sexes.

Whether you're male or female, if you lift weights, you're likely to gain muscle and strength at about the same rate — even though guys usually start with more testosterone than girls.

Men tend to get stronger faster than women when lifting very heavy weights, possibly due to differences in how their muscles and nerves respond to intense training.