When doing push-ups, the narrower the arm, the better the exercise effect will be on the inner side (right in the middle) of the chest muscle. Be careful not to stretch your arms too straight or bend them too much. Don't think that a large amplitude will have a good effect on the joints. Take your time. At first, you will definitely shake badly, because it will be fine if you are bored for a long time. Continue to develop your chest muscles in the middle for a long time, and you will gradually see your cleavage (calm down, this is serious).
Don't cross your shoulders if your palms are wide apart. This is good for the outside of the pectoral muscle, that is, the part next to the creasing fossa. It's cool to hold the side when wearing sleeveless clothes.
Pull-ups have the best effect on the inner side of pectoral muscles, especially on the upper side of pectoral muscles. That's all that matters. Whether you watch it or not, you have earned a man's chest muscle. Only when the upper strength is strengthened can you pull up the whole MIMI, and pull-ups have a very, very significant effect on the lower chest muscles. Stick to it, your chest muscles will be as prominent as in the movie, but they will not sag, be elastic and have strength.
If it is wider than the shoulder, it is mainly helpful to the outside of the pectoral muscle. It looks like an inverted triangle. Perfect for streaking on the beach, full of confidence. If you use flying birds, it is specifically aimed at the upper part of the pectoral muscle. These can effectively enhance the strength of the upper limbs, and the strength of the lower limbs needs to practice leapfrog and squat.