I’ve read of a Japanese body building practice that involves using a blood pressure cuff to restrict the dispersal of blood. The muscle marinates in its metabolic waste, which has an anabolic effect. Don’t know what they do for muscles in the torso.

https://www.outsideonline.com/health/running/you-should-prob...

> Don’t know what they do for muscles in the torso.

Nothing, I guess? All the articles I have found only refer to arms and legs. Restricting blood flow in the torso would be difficult (not to mention pretty dangerous), so the method probably can't be applied there...

Searching for BFR will uncover resources for this style of exercise as it's common in physiotherapy and bodybuilding.

Just a note though: avoid the bodybuilding "bro science", there is an established method to calibrating BFR that doesn't merely involve putting wraps around the arm or leg and hoping for the best. The main harm is cutting off too much blood flow by using a cuff that is either on for too long or can gather in a way that progressively cuts off circulation during the movement.

The core advantage of BFR is one can use a lighter weight to achieve similar results, which can improve the surrounding conditions of your limbs (joints/tendons), it is no less tiring or strenuous(on the muscle) than regular exercise.

Look up 'zone 2' training, especially in cycling and running.