You can exercise at the age of 30, in no particular order, but after the age of 30, your physical function may affect your metabolism and digestion a little. In addition, the fundamental reason of exercise is to constantly stretch and contract muscles to make them more flexible. I saw an old man in his fifties with good lines. He said that he didn't join sports until he was 30 years old, but his muscle composition is different from that of young people, and his muscles will gradually shrink, but it is not harmful to his body.

You don't have to have muscles to run a gym. It's just a personal hobby. You can open it if you like. Nobody cares about your muscles. I have met many owners who run gyms, but not all of them are muscular.

The examination of fitness instructors mainly depends on your diet, physical and mental knowledge, and the skills of regulating the human body, but there are not many requirements for your muscles.

As long as you can speak, customers think you speak well, of course, customers will come to your door, and it is also possible to invite a few muscular men to be strong.