Muscles are the most grateful. If you give him appropriate stimulation, he will definitely respond to you, and it will grow thicker and harder. Almost all the standard movements are very tiring. If the action is not standard, that is, using coordinated muscles to do the action, the effect will be greatly reduced.
Therefore ... every time you exercise, you have to feel a little tired to complete the training, and you have to warm up first.
Stop moving and have a good rest. Let him recover by himself.
I am a doctor. Who did you say you listened to?