He addresses them with that statement. There are plenty of women that are in similar weight classes as men but you don't see any in male sports.
Even though male sports does not have a gender requirement. This is essentially an indirect way of saying that there are biological differences between male and female that go beyond weight.
There are various differences you could point out. Males have lower body fat %, which means more muscle. Their bones are shaped differently and are more dense. Men tend to be more aggressive and competitive. Men tend to have stronger bones, joints, tendons, and ligaments.
Men have more red blood cells, their hearts are bigger so they can pump more blood, and greater lung volume relative to body mass. So even a male and women same weight and height the man will be able to circulate oxygen more quickly.
There are many more examples if you go do some reading.
One of the differences may not be huge by themselves. But when you take the differences above and combine them, it creates a situation where in almost all sports, men play virtually unopposed by women.
Look up the Serena Williams interview. She's undoubtedly the best female player in the world. She doesn't stand a chance against a the 203rd best tennis male player.
This difference even applies to areas like chess. The highest ranking a woman ever got was 6th in the world, Judith Pulgar. Amazing player, but out of the 2500 or so grandmasters in the world, 42 are women.
Some of these differences can be explained by women around the world not being encouraged to play chess, but that does not explain all.
There are large biological differences when you look at the population in a statistical sense. And when you look at the most extreme samples from the edge of the normal distribution.. that's where the best athletes / chess players are going to come from.