Lighter Weights, Bigger Muscles: How Effort Drives Hypertrophy

When you see the biggest person in the gym, you might think they’ll be lifting the heaviest weights. You have to lift massive weights to build massive muscles, right? Well, not really.

“There’s a lot of talk about certain routines, and a lot of it comes from training methods used in former Soviet countries where many peopel were using steroids,” says Stuart Phillips, PhD, a kinesiology professor and research director at McMaster University. Some of it also comes from a study from 1946 that was misunderstood. While helping soldiers recover from World War II, army doctor Thomas DeLorme said that heavy resistance training was better for building muscle then activities like walking or biking. For decades,many people thought this meant only heavy weights were helpful,says Dr. Phillips.

But the more scientists study this, the more they find that lifting heavy isn’t necessary to build muscle, or what experts call “hypertrophy.” Recently, Dr. Phillips led a large analysis published in the British Journal of Sports Medicine. It looked at 192 studies with over 5,000 people to find the best way to build muscle. What his team found surprised many. “You can lift lighter weights, and if you put in a lot of effort, they’re just as good as heavier weights for getting bigger.”