What is the optimal way to gain muscle mass with a minimum of post-training fatigue?
Is it a good way to train with only one hard session a week?
(Here I am looking for how to organize my training and intensity, not massage, supplements yoga etc.)

What should happen at a muscular level? (To have training effect without increasing fibro)

Check out the Doggcrapp method (seriously).

Most sources say it is for advanced bodybuilding?
Can you point out what is relevant in this context?

Valentine