Bare-handed exercise will not hinder the growth of height, and weight-bearing exercise will be dangerous;

Remember to rest your muscles when you practice them. The muscles of one part should rest for at least two days at a time. Long muscles are like long hand cocoons. You should put on the skin first, then restore the worn skin, and then start to grow extra hand cocoons.

To practice muscles, we must practice at high density and concentrate on solving them in a short time. Just like if you do push-ups for one minute, you won't be tired after doing them all day, so you will be tired after doing 1 minute.

Remember these two points, you should make rapid progress. At your age, you don't need to strengthen your muscles deliberately. You just need to do a little basic work, and then start heavy exercise when you are almost an adult.