It does have an impact. I have practiced for many years and experienced a lot. When I first started practicing actual combat, I was afraid of any attack. Afraid of hooking, abdominal pain, straight fist, sternal pain and tearing. Later, because I can practice hard, my abdomen is stronger, but my sternum is not muscular. Besides, the Sanda athlete who was not the finale in the last Sino-Thai competition was hit by his knee and his sternum was sunken. So you see, in the competition, the average person can bear the ordinary straight punch to the sternum, but the real hard punch can't. Later, I learned that the resistance of the sternum to beating is muscle-free, so it is not as simple as practicing hard muscles. Just like hard qigong, you have to exhale briefly at the moment of being hit to cushion the impact caused by your opponent's fist. Because of the heavy chest pressure, I found that if I can't stop it, it is easy to resist a few heavy attacks with hard qigong.

You have to remember, like thighs and abdomen, they are all muscles, and they are all hardened by anti-beating exercise, but calves, calves, forearms, sternum, ribs and collarbones can't be trained like muscles. Don't hammer hard on weekdays. Hammer lightly to make bones harden slowly, and then learn to exhale when being beaten. This is the trick of bone defense.