Peter mcginnis, a professor of physical education at new york State University and a sports association consultant, pointed out that generally speaking, if men can do 15 push-ups every day after 40 years old, they should be able to ensure their physical fitness in sexual life. If the physical strength is poor, you can start with simple exercises, 50 cm away from the wall, and push the wall with your arms to support your body, 12- 15 times each time, and practice 3 times a day. With the growth of physical strength, gradually change to prone position, pay attention to keep your back straight and tighten your hips and abdomen every time you exercise, and the number of times will change from less to more.