Pretty much everyone believes that lifting weights is what makes your muscles grow. In fact that belief is so common, that it’s almost absurd to suggest anything else. Well, as I’m about to explain, lifting weights to build bigger muscles is a completely backward way of thinking.
First, some background. The scientific word for increasing the size of muscle is called “hypertrophy.” That’s a fancy way of saying that your muscles will grow larger, if you increase the size of the muscle’s cells and fibers. And how do you do that? You do it by applying the “principle of overload.” That means that your muscles are stimulated to grow larger if they do work that is over and above what they are used to doing. The body “adapts” to this increased workload by making the muscle cells/fibers grow larger. The more they’re overloaded, the larger they grow. (Always consult a physician before beginning or changing any fitness program.)
The old phrase, use it or lose it, has a lot of truth to it. If you challenge your muscles, they will adapt and grow. If you don’t challenge your muscles, e.g. become a couch potato, your body will adapt to that too and guess what? You lose muscle tone and mass. As we age, we tend to lose muscle mass anyway, so by not doing strength training, you’re just letting Mother Nature take her toll all that much faster.
Now onto the real issue. Is lifting barbells and dumbbells (weights) really what makes your muscles grow? Technically speaking, the answer is no. What really makes your muscles grow is a strong **contraction** of the muscle tissue. When you contract a muscle strongly enough, it creates small tears and, during the recovery or rest period, the muscle rebuilds itself just a little bit larger. So it’s not really lifting weights that causes your muscles to grow larger, it’s the contraction of the muscle (first and foremost) that is caused by the lifting of the weights. The weights are the secondary player. You tear down the muscle fibers during strong contractions of the muscle, and then they recover larger in response to that previous overload.
How do you make your muscles contract strongly, so that you’ll create those little tears (that create the soreness afterwards)? For many people, it’s lifting weights. It’s the resistance against gravity or against a stack of weights that allows you to get a great contraction in the muscle you are targeting. Maybe that’s splitting hairs, but it is the proper (biological) way to think about how the body increases (or decreases) muscle mass. You should not be thinking about “lifting the weight,” so much as you should be thinking about contracting the muscle.
