1 depends on whether the chest is breast enhancement or fat. After exercise to lose weight, the former will not be much smaller, and the latter will be much smaller.

Running is strenuous exercise, but there is no muscle in the breast, only ligaments and skin play the main supporting role. You need to wear a professional sports bra when you exercise, that is, the tighter you hold it, the better it is to stick to your body. Madonna wears three sports bras when she runs.

3 Doing anaerobic exercise after running, such as standard push-ups (kneeling posture does not have much effect), although it can not significantly reduce the possibility of chest becoming smaller, it can make the chest muscles bigger and the chest stronger.

Remember to supplement protein more, and don't eat less meat, eggs and milk.