Proper push-ups and sit-ups can exercise on the premise that the body can bear it. Long-term persistence can improve immunity. The most important thing is long-term persistence. You can't fish for three days and dry the net for two days. The time and amount of exercise should be gradually increased to avoid the discomfort caused by excessive exercise and keep the body in a balanced and healthy state, about 50 a day.

Extended data:

It is a basic training in daily exercise and physical education class, especially in military physical training. Push-ups mainly exercise the muscles of upper limbs, waist and abdomen, especially the chest muscles. It is a very simple but effective strength training method. Beginners can practice push-ups in two groups, each group 15 to 20 times; Athletes with a certain foundation can do 3 groups, 20 times in each group; High-level people can try four groups of 30 to 50 push-ups

References:

Fitness meal-Baidu encyclopedia