How Do Muscles Grow?


Like weight-loss fads, there are hundreds of pitches and voices clamoring to tell you how to grow your muscles and get fit or ripped. And like weight-loss, it becomes hard to filter what really works, let alone what works best.

That’s why understanding how muscles grow is a vital part of understanding what exercises, diets, and supplements actually help you boost muscle mass and make your workout time pay off. So first things first:

How do Muscles Work?

What we usually call muscles are specifically skeletal muscles (rather than other muscles like cardiac, aka, the heart), which are collections of muscle “fibers” that are sent signals to contract, working together to exert power.

That means there are actually two different ways to get stronger: the first and most obvious is to increase muscle mass, so you have more numerous, thicker fibers to contract when you lift or push something. The second, less commonly known is by your motor neurons becoming better at sending those signals, which is why a lot of strength is gained when you just start working out. This is also felt when muscles “swell” during and after a workout due to increased blood flow.

Once your body starts to become more efficient at activating your muscles is when real muscle growth tends to occur.

The Biology of Muscle Growth

Muscles don’t actually grow while you lift weights: when you work out, your muscle fibers stretch and tear from being pushed beyond their limits. It’s only afterward, when you’re resting, that satellite cells activate and repair your muscles, fusing them back together by forming new strands.

Now you’ve got more muscle mass, which means more fibers that can contract and handle more weight. Which means it’s time to up the weight on your lifts, so you go beyond your limits again and cause new tears, beginning the process all over again.

That’s why there’s no super-fast way to grow muscles, and why rest and nutrition is so important. If you don’t give your body that time to form new fibers and repair itself, you not only won’t see proper growth, you might even lose muscles.

The full cycle of regeneration differs for everyone, and is usually between 24-48 hours, which is why so many guides only advocate going the gym three to four times a week. But there are ways you can make those sessions more effective.

Hormones and Nutrients

Along with getting plenty of rest, your body also needs the basic material to build new muscles. That where hormones come in: a healthy amount of testosterone helps regulate the repair process, and a balanced diet with enough protein to create new muscle fibers.

It’s important to note that if you begin working out harder without being careful about your calorie intake, you are likely to increase your muscle mass *and* your fat tissue, so if you want to keep your weight stable or get a more “ripped” appearance, it’s also important to keep calorie intake regulated, since working out hard tends to increase appetite as your body tries to make up for the energy it uses.

For other help in your workouts and body building, there are some supplements that help make the process easier and more efficient. For example, human growth hormone can help accelerate the muscle repair and growth process while you rest. Find out more here!