Why don't you have enough rest time after practicing dumbbells, so you can do it for two days in a row and you can't even do one the next day?

The main structure of muscle is muscle fiber, and the growth of muscle is to tear the fiber, so that the torn place can be repaired nutritionally and the muscle becomes thicker and thicker. The principle is that you keep wrapping tape around your hand, and it gets bigger and bigger. After every exercise, the muscles are in a period of self-repair, and there is definitely no strength.

Simply put, rest for at least 2 days at a time for each training, so that the muscles have time to grow. Pure hand tour, giving points.