First, you should eat meat and drink milk. If you are malnourished all day, you will never be strong. At your age, you are growing up and need nutrition. It is necessary to eat a catty of lean meat every day. Try to eat steamed bread, which is better in the north. Because this kind of pasta is the highest in protein. Eat less noodles, rice and other foods. On the one hand, it is difficult to digest and easy to eat. On the other hand, these foods are produced in the south. The same rice is cooked once a year in the northeast and twice or even three times a year in the south, so the food is less nutritious. In addition, don't eat snacks, drinks, alcohol and tobacco. As long as you eat and drink water, you can eat fruit. If possible, try to eat red meat, such as beef, horse meat and donkey meat, followed by pork and mutton. Chicken is the most nutritious. If the meat is not enough, you can eat tofu instead. Tofu Try to eat old tofu, such as tofu skin and dried tofu, and don't eat tender tofu. For example, Japanese tofu is not as delicious as our traditional brine tofu.

Secondly, punching sandbags won't help much. I suggest you skip it. If you think leapfrog is easy, put rice on your back (you can put rice or sand in your schoolbag and jump on your back or hold it), leapfrog 100 meters. And practice 100 meter sprint (short-distance accelerated running). Don't punch too much, just punch 10 times at most. 100 meter 2-3 times is estimated to cause pain all over the body. You can exercise every other day instead of every day. But every time I exercise, I must be weak and sore. If you don't feel anything after exercise, the load is not enough. I suggest you increase the weight of the rice bag.