You can completely recover any muscle in four days, but you have to work harder. Practice recumbent bench press on chest muscles, and start 4 to 6 groups of flat chest for 3 months, with no less than 8 in each group. There are more than 4 groups in the upper chest and more than 4 groups in the lower chest. Add the number of groups after three months. Abdominal muscles are difficult to practice, with 50 to 80 sit-ups a day and 20 to 40 a month. It is valid for three months.