Doing light weight training with blood flow restriction doesn't change the space around muscle fibers any more than heavy weight training in regular active people — after six weeks, both seem to have...

For people new to strength training, lifting light weights with restricted blood flow works just as well as lifting heavy weights for building muscle size over 6 weeks.

For people who exercise casually but aren’t trained, doing light weightlifting with blood flow restriction helps grow fast-twitch muscle fibers almost as much as lifting heavy weights — and after 6 weeks, the difference between the two isn’t big enough to matter.

Some people grow more muscle with regular heavy lifting, others grow just as much or more with heavy lifting plus blood flow restriction — there’s no one-size-fits-all answer.

If you lift heavy weights with a special band that cuts off some blood flow, it doesn’t make your muscles stronger or bigger than just lifting heavy weights alone—even though your muscles feel more burned.

In healthy young men, two different resistance training methods—training until muscle failure or using blood flow restriction with mixed intensities—produce similar increases in thigh muscle size after six weeks, suggesting that reaching muscle failure may matter more for muscle growth than how heavy the weights are or how much total work is done.