I am a college student. I exercise every day. My suggestion is: you buy a pair of dumbbells, press 13 pairs in bed and rest 1 minute. If you want to increase the muscle content of chest muscles, you should use heavy objects. If it is shaping, use a small weight many times. Do push-ups at the lower edge of the chest muscles, and put your hands on the table 50 cm off the ground, in groups of 30 and 3. If there is a side, you can make a horizontal bird. 13 is a group and 3 groups.