Q: What is “blood flow restriction training”? I hear it helps with muscle gain and tone.

A: Blood flow restriction training is a way to get the benefits of weight training while using much less weight, making it perfect for anyone with an injury. It works using constricting bands that act as a kind of semi-tourniquet. Wherever you place the bands – arms, legs – you slow or restrict blood flow to the working muscles in that area (such as the biceps in the arms). With blood flow restricted, you then perform the exercise (for example, the biceps curl), but you do the exercise with far less weight than you’d normally use for a biceps curl. And, amazingly, you get results.

We know that besides building muscles, resistance exercise – that is, contracting the muscles against external resistance such as using weights in strength training – has enormous health benefits. One study, published in Medicine & Science in Sport & Exercise, found that lifting weights for even one hour a week lowered the risk of heart disease by a minimum of 40% all the way up to 70%. But we also know that for many people, especially seniors, weight lifting may have some drawbacks.