Most people's left and right pectoral muscles are not very paired. I haven't seen your picture, and I don't know how different it is. If it is within the normal range, you don't need to pay special attention. In my experience, there should be little difference between your left and right chest muscles, which may be caused by your psychological effect. The function of pectoral muscle is mainly to drive the two arms to move inward, which is rarely used at ordinary times. If you want to exercise your unilateral chest muscles alone, I'll give you several methods: 1, unilateral push-ups. Of course, most people can't do push-ups on one limb. You can do it. If you want to practice your left chest, hold the ground with your left hand. 2, one-sided push, when we push the heavy object upwards, the upper part of the pectoral muscle will also exert force, so that you can push the dumbbell upwards with one hand and exercise the unilateral pectoral muscle.