Have you ever wondered if foam rollers actually work? Or are they just another fleeting trend in the world of fitness? And if they do work—how important are they? The answer to these questions may surprise you…

First, it’s important to understand the part of the body the foam roller is intended for: the fascia. Ok—so it’s not technically a body part. The fascia is a connective tissue made up of glycoproteins (which sponge up water), fat cells, and collagen fibers (the body’s strongest protein). It runs through your entire body, holding muscles and bones in place and even supporting their movement. Because the fascia system stretches all throughout the body, it plays an integral role in your day-to-day life. Many of the pains we attribute to sore muscles or aching bones are actually tight or irritated fascia. Conversely, taking steps to maintain a healthy fascia can lead to increased energy, better sleep, and overall greater comfort.

The fascia is an incredibly flexible and durable material, but just like muscles and bones, it is prone to damage when proper care is not taken. Many of the repetitive movements in exercises also engage your fascia, which can be over-exerted if you’re trying to do too much too fast. Even everyday activities—taking a walk, sitting at a desk—can take a toll on your fascia.

But there’s good news: taking good care of your fascia is incredibly simple! If you’ve ever had to massage scar tissue after a surgery or deep cut, you’ve already had some interaction with your fascia. The reason that massaging scar tissue works is because it has the same collagen base as your fascia, making it elastic and pliable. Similarly, regularly massaging the fascia will help to loosen tough spots and also unblock any build-up that may have accrued from a recent injury or misuse.

So why use a foam roller? The answer mostly boils down to convenience. There’s any number of ways to give your fascia the regular rub-down it needs, but short of hiring a personal masseuse, a foam roller is likely your best bet. The problem may just be that it’s too easy. As often happens, it’s hard to believe that something so simple can have such drastic effects. It’s easier to believe in something if you’ve had to pay a lot for it or work hard for it. But as time goes on, the foam roller revolution is not backing down. From professional athletes to doctors, the health community is realizing that this simple step is indispensable in the quest for overall good health.

How does the foam roller help exactly? The cylindrical shape of the foam roller allows you to apply concentrated pressure to specific areas of your body. For example, when using it on your calves—a favorite for those whose work requires a lot of standing or walking—you can use both hands to press the roller against your muscle, focusing all of that pressure to just the point of contact, and then rotating the roller to move up or down the muscle as needed. The same technique can be applied to other parts as well, such as thighs and arms.

One of the most common misencounters with fascia is plantar fasciitis—the painful inflaming of the fascia in the sole of your feet that can lead to other serious health issues. Every year, more than 2 million people are diagnosed with plantar fasciitis, especially runners. You can help prevent this debilitating condition by regularly using a foam roller on the soles of your feet. Simply stand facing the roller and place the sole of one foot on top, applying weight to adjust to what feels best. Careful: you may want to have something to hold onto for balance at first. Because we are always on our feet, they often get hit the hardest. And because our bodies act as one long chain, what happens at the bottom can work its way all the way up to the top.

So whether you’re looking to give your body some reprieve from your workouts or just want to feel better after a long day of work, using a foam roller can help ease sore muscles and keep your joints from getting stiff. And with an abundance of online instructional videos, you can search for ways to use your foam roller for specific problems, or find general routines to keep your body in tip-top shape.