When you use a foam roller to relieve your sore calves or quads after a workout, you might take any bruising that develops later on as proof that the tool is working. As the saying goes, things have to get worse before they can get better — even when it comes to recovery techniques, right?

Not exactly. Here, a physical therapist breaks down the causes and potential risks of bruising after foam rolling — and shares tips on how to minimize those post-rolling tender spots in the future. 

ICYDK, bruises typically form when the small blood vessels near your skin's surface break (sometimes from the impact of a blow), causing blood to leak out and a dark, tender mark to appear, according to the Mayo Clinic. But can rolling a piece of foam up and down your body cause the same reaction?

Turns out, it's common to bruises after foam rolling, but it's not a sign of a job well done, says Leada Malek, P.T., D.P.T., C.S.C.S., S.C.S., a board-certified sports specialist and physical therapist. Instead, bruising is often an indicator that you foam rolled too hard, for too long, in the wrong areas, or did a combination of all three, she says. 

There's no official protocol for how long you should spend foam rolling, but generally speaking, you'll want to use the tool on one spot for just 30 to 60 seconds, moving it slowly along your body, says Malek. If you end up foam rolling for longer than that, you run the risk of bruising, she says. (Related: Common Foam Rolling Mistakes You're Probably Making)

Similarly, there's no specific recommended pressure to apply while rolling, as what feels too hard for one person may feel too light for another, but if you're pressing to the point that you feel sore or tender after you finish, there's a chance you'll experience bruising, says Malek. "Definitely going over a muscle for too long or too hard can result in bruising," she adds. 

Even if you're using a just-right pressure for a short amount of time, you can still develop bruising if you're using a foam roller on a thick, noncontractile tissue, such as your IT band, or on super tight muscles, says Malek. "The goal with the foam roller is to get the muscle to relax a little," she explains. "But if you were to roll over your IT band or something that is excessively stiff, it might fight back on you." The same reaction may occur if you roll close to your joints (think: you're rolling down your quad close to your knee), as the tissue composition changes in that area, adds Malek. "It's not pure muscle anymore — it becomes a little bit more tendinous, and that's not exactly soft and squishy," she says. In other words, that tissue doesn't have as much "give," so applying a rock-solid foam roller to it could cause bruising to develop.

Rolling on or near a bone can also trigger nasty bruises, says Malek. "If you were to curve your low back and just roll up and down on the lumbar spine, that's not going to feel very good," she says. "So move off to the side a bit so you get more of the muscle bulk as opposed to the actual bone."

Of course, you may still develop bruising after foam rolling if you suffer from a blood-clotting problem or a blood disease, which can cause you to bruise easily, according to the Mayo Clinic.

Foam rolling to the point of bruising may seem like NBD, but in some cases, doing so can have serious health effects, including hematomas, which cause swollen, raised, painful bumps, says Malek. Just like bruises, hematomas develop when blood vessels break, but rather than being reabsorbed by the body, the blood clots in an organ or tissue, according to the National Cancer Institute. Hematomas can last a month or longer and may require medical attention (think: surgery), according to the Cleveland Clinic. "Those develop more commonly after an impact, like if you've been struck at the leg, [but] you could potentially run into those [with foam rolling]," says Malek. 

What's more, if you're consistently developing bruises, your muscles and tissues will only stay tight, says Malek, as bruising activates your body's inflammatory response which can cause stiffness. News flash: That's the exact opposite of what you're hoping to achieve by foam rolling, says Malek. 

If you're constantly waking up to purple spots the day after a foam rolling session, there are steps you can take to keep any bruising in check. First, avoid rolling near your joints, bones, and tight muscles and tissues. Then, apply less pressure to the areas you're foam rolling and spend less time treating those spots, suggests Malek. If you haven't already, you can also try a softer, non-textured foam roller, which puts less pressure on your body and won't dig into your skin, she adds. If all else fails, try a handheld muscle roller stick so you can easily control the pressure, recommends Malek. (Related: The Best Foam Rollers for Muscle Recovery) 

TL;DR: "If you're developing physical bruising after foam rolling, I would be very mindful of it and switch it up because you shouldn't be walking away from a foam roller with a bruise," says Malek. "That's not the goal of using a foam roller."