Why do two men support each other with their pectoral muscles when challenging each other?

I don't think it's necessary to use chest muscles. And most people don't have chest muscles. You have to exercise your chest muscles to get out. 1: Chest expander (that is, a spring rod, holding Bai Wan's kind, dumbbells are used to enlarge muscles, and the spring rod expands the chest area. ) 2: tudou. com search: macho man teaches you dumbbell fitness 1 ~ 10 (professional enough) 3: You can't eat normally! Will become lean meat, like Bruce Lee, you can choose to eat protein powder, pqfitness and so on, milk, beef. You can also eat boiled eggs, soybean milk, glucose and so on.

Personal suggestion: only increase the difficulty every 1 month, and avoid adding groups every day, so you will give up sooner or later. Beginners are divided into three steps: persistence every day, standardized action and slow action. Each action 12 times is a group. Doing too much will turn into endurance training. Endurance fitness and increasing times are not recommended. When the muscles reach the limit, the number of increases will not increase, and only dumbbells can get more exciting muscles.