When it comes to fitness, I have deep feelings and opinions about many men and women, so I won't go into details here.

The difference between male and female fitness is that

Men secrete androgens, while women secrete estrogens.

Therefore, men need much shorter and stronger time to practice muscles than women, and women need to secrete female hormones, so it is difficult for them to practice muscles, and they will only practice their body muscles more flexibly, not big muscles. So men practice muscles and women practice mermaids.

This is the gender difference in fitness.