Most people have experienced a fair amount of muscle knots in their lifetime, and they’re certainly not a pleasant experience. Think stress-induced tension, tenderness, soreness — the works.

But have you ever wondered what these pesky, bumpy adhesions actually are? We answered all your questions below, and provided tips on how to release knots and tips for self-massage.

What are knots?

The answer isn’t a straightforward one: No one knows with complete certainty what muscle knots are made of, the New York Times‘ Gretchen Reynolds reports. However, Considerable spoke with a personal trainer to get as close to an answer as possible.

“Knots, also known as adhesions, are muscle fibers that get stuck together causing limited range of motion, improper muscle firing and aches and pains in the body,” Rachel Prairie, a personal trainer at Anytime Fitness tells Considerable.

According to the trainer, fascia, the biological fabric that holds us together, forms a sheath over our entire muscular system essentially turning the body into one big kinetic chain. Because of this, “a knot in one part of your body can eventually cause dysfunction in another area as your body tries to compensate at the site of the troubled area,” Prairie explains. For example, an adhesion in the calf might end up causing pain in our back.

How can I release knots?

Getting an adequate amount of sleep, exercising moderately, alternating between heat and ice applied to the affected area, western medicine such as anti-inflammatory medications, and eastern remedies such as acupuncture are all effective ways of preventing and/or releasing muscle knots.

And, according to Prairie, a few minutes of self-myofascial release (also known as SMR or self-massage) using a foam roller, medicine/tennis ball, handheld roller or other assistive devices can do the trick. “Think of [SMR] as brushing your hair,” she tells Considerable. “If you don’t brush your hair, it gets tangled. If we don’t roll out our muscles, they get adhesions.”

Below, Prairie provides SMR tips for using a foam roller (which are available at most gyms and can be found in almost any sporting goods retailer for a minimal investment).

A few foam rolling tips

  • Choosing the right foam roller: There are several different types of foam rollers and they all serve a different purpose. Less dense foam is for beginner rollers looking to ease in. Longer rollers are great for focusing on your back, while shorter rollers are typically used for rolling out arms and legs. You can also opt for a narrower roller for more targeted rolling.
  • How to roll: Roll slowly and when you find a tender spot, focus in on it by rolling back and forth until you feel it soften or release. Make sure to roll slowly so that the superficial layers and muscles have time to adapt and manage the compression. And, while you may be tempted to roll over a knot for an extended amount of time, give your muscles a rest. Too much focused rolling may cause damage and bruising.

Never roll over these areas

  • Lower back: The muscles in your back will always instinctually try to protect your spine and rolling it can cause long lasting spasms.
  • IT band: Studies show that your IT band, which runs the length of your outer thigh, is actually a very strong piece of connective tissue, and it cannot be rolled out — you may just be irritating it.
  • Neck: There’s not enough dense tissue for rolling here which may cause more harm than good.
  • And in general, don’t “over roll” anywhere: You may cause bruising and damage tissue instead of quickening muscle repair; 30-90 seconds on each area should be more than enough.