You can make your muscles grow bigger by lifting very light weights if you restrict blood flow to your arm or leg — it tricks your body into thinking you’re lifting heavy.

For most people, lifting light weights with blood flow restriction builds muscle just as well as lifting heavy weights — making it a great option if you can't lift heavy.

When you do blood flow restriction training—like wearing tight bands on your arms or legs while lifting light weights—you build muscle mainly because your muscles fire harder and earlier, not because of the burn or buildup of waste products.

People who already lift weights regularly get stronger and build more muscle from low-weight exercises with blood flow restriction than from heavy lifting, making BFR-RT a powerful tool for advanced athletes.

BFR training doesn't make you stronger at lifting your heaviest weight — it helps with endurance and muscle size, but not with max strength tests like a one-rep max.

When you do BFR training, your muscles grow more in the middle and lower parts of your thigh than near your hip — meaning the effect is strongest where the blood flow is most restricted.