1, the difference between male and female hormones is dozens of times, so even if women and men do strength training, it is difficult to build strong muscles. Although men can develop well-developed leg muscles through strength training, running is an endurance exercise, and leg muscles can only be developed through sprinting.
2. Running is endurance exercise, and endurance exercise can't build big muscles. For example, in favorite running (especially long-distance running) or riding, slow muscle fibers will gradually increase, but the main force of muscle increase-fast muscle fibers will not increase significantly, or even shrink.
Some people think that running will make legs thicker, but in fact, for most women with thick legs, it is mostly caused by fat accumulation. Even if you are a mixture of muscle and fat, correct running training can also reduce fat and improve calf lines.