Until pretty recently, the conventional wisdom about building muscle was that it worked via a system you might think of as “tear and repair” – the idea being that working out causes microtears in the muscle fibres, which trigger the body’s repair processes, encouraging the muscles to come back bigger and stronger.
That’s why many old-school trainers will tell you that there’s no gain without pain, and why a lot of bodybuilding advice includes increasingly byzantine ways of pushing your biceps and triceps to the point where you can’t do another repetition: the more trauma you can cause, the thinking goes, the more “swole” you can become.
