Fitness, 20 times per movement, five groups, what do you mean?
That is, an action is repeated 100 times, but it is divided into five parts. You can have a proper rest between these five parts, otherwise you can't achieve the desired effect if you do it for a hundred times at once, and you may also cause muscle strain. Therefore, when exercising, we must pay attention to science, not be impatient, and persist for a long time.