Compared to a tricked-out treadmill or shiny set of free weights, a foam roller may look like the plain Jane of the gym. But learn how to use this simple cylinder made of hard foam correctly and it may wind up being your new favorite workout buddy.

Foam rolling has long been a fixture of physical therapy. In recent years it’s become popular among athletes and other fitness enthusiasts. Research has found that foam rolling is an effective way to reduce achiness immediately after exercise. It also can alleviate delayed onset muscle soreness (often referred to as DOMS), which is the pain that sets in 12 to 48 hours after exercise, according to Duane Button, PhD, assistant professor in the School of Human Kinetics and Recreation at Memorial University of Newfoundland in Canada and a leading researcher on foam rolling.

What’s more, says Button, foam rolling may be better than static stretching — the kind your gym teacher made you do at the beginning of class — for increasing range of motion as part of a warm-up.

Even if you don’t exercise, you can benefit from using a foam roller. “You’ll be more flexible and better able to do day-to-day activities, like bending down to pick something up,” Button says.

What is foam rolling?

Foam rolling involves positioning a roller against a tight, achy body part and using your weight to apply enough pressure to massage knots in the muscles.

It’s basically a form of massage that’s known as myofascial release. Soft tissue in the body, including muscle (“myo”), is surrounded by connective tissue called fascia. Fascia that becomes stiff and tight may form adhesions, or “knots,” causing pain and stiffness in the muscles it surrounds.

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How to use a foam roller

The key to using a foam roller is to position it so you can put body weight on the area you want to work on. Button offers these examples:

To roll the sides of your hips: Sit on the roller with your legs straight in front of you. Cross your right leg over the left so your right ankle rests on your left knee. Place your left hand on the floor behind the roller, just beyond your upper body. Lean slightly on that hand so that your body shifts a bit toward it and the roller is positioned under the side of your left hip. Press forward and backward with your left leg so the roller massages the area. Do this for 25 or 30 seconds. Switch legs and repeat.

You can use a similar technique to roll your hamstrings, quadriceps, inner and outer thighs and calves.

To roll your upper back: Lie on the floor and place the roller under your shoulders. Keeping both feet flat on the floor, move up and down so the roller massages your upper back. When you feel a painful knot, slow down and roll carefully over the painful spot to release the knots.

Because you’re disturbing the fascia, foam rolling can be painful, especially the first few times you try it. You can control the pain by putting less weight on the area you’re working. In other words, if you’re rolling your legs, place more weight on your arms. As you become better at it and your body becomes more accustomed to the sensation, you can put more and more weight on the areas you are rolling, Button says.

How to roll safely

Button offers these safety tips for using the roller properly:

  • Never roll directly on a joint or a bone. There’s no benefit to doing this, and putting pressure on a joint could lead to injury.
  • Never roll on your stomach. You’ll massage internal organs, not muscle.
  • Don’t roll on your neck. The sensitive tendons and muscles in your neck may not be strong enough to handle the pressure.
  • Use care if you decide to roll on your lower back. Many experts recommend against rolling on the lower back. If you do, Button says to use a large roller. A small one may cause the muscles that support your spine to contract.

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  • Don’t roll for more than 30 to 60 seconds at a time. Rolling for longer durations has not been tested. “It’s okay to roll for thirty seconds or a minute, then repeat,” Dr. Button says.
  • If it hurts too much to use a foam roller, Button suggests starting with a roller massager — a rolling pin-like product that gives you more control over the amount of pressure you apply to a body part. (Theraband makes a good one.)