If you’re struggling with knee pain, pay attention to your treadmill incline

As much as I love running, I know a number of people who refuse to do it for a number of reasons. Some people say that they simply don’t like it, others prefer lower-impact workouts like yoga and Pilates, and then there are those who don’t run because they have knee pain. I get it, it’s not for everyone.

But since running and walking are pretty foundational movements in fitness, I bring good news: If the high-impact motions make your knees hurt,  Precision Run—the new running studio in New York, based off of the Equinox class—instructor and founder David Siik says that you can use your incline to help lessen the impact on your knees.

“Adding incline reduces certain forces acting on the knees, which can create a much more comfortable experience,” says Siik. “The other bonus is a little extra work on your glutes, quads, hamstrings, and calves, and really improving strength.” And it’s not like you have to hike Everest (bless up for that) to reap the benefits on your treadmill. “While there’s no perfect incline for every body type, the one to three percent incline range is a great place to run for those with knee issues or recovering from a knee injury,” says Siik.

“Adding incline reduces certain forces acting on the knees, which can create a much more comfortable experience for those with knee issues.” —David Siik

Corinne Croce, physical therapist and co-founder of Body Evolved, pretty much echoes Siik, noting that a small incline percentage can make treadmill workouts doable (and beneficial) for bad knees. “A very slight incline can help mimic outdoor walking or running, which is helpful for functional training,” she tells me. “An incline requires more effort, so lower speeds can be used to have lower impact while still maintaining intensity. Using one-to-two percent incline is ideal, and three and under is the safest, especially for those with injuries or joint pain.”

To get into the whole Goldilocks explanation on how different inclines impact your joints or your knees, a steep incline can undo all of those perks. “Too high of an incline alters mechanics unfavorably, because often we rely on quads to execute the intensity a sharp incline creates, and we also use less ankle mobility with too sharp of an incline increasing knee pressure,” says Croce. Siik adds that steep inclines—especially on the wrong speeds—can compromise areas beyond the knees. “Your body needs to dial further forward on bigger inclines, decreasing the angle between your knee and chest, which can expose the lower back to strain or injury if it’s too steep and too fast,” he says.

If you keep the treadmill or the incline completely flat, it’ll work other parts of your body that can add force onto your knees. “If you have knee issues or injuries, it can make those issues feel worse,” says Siik. Tiffany Zarcone, DPT, adds that “a zero percent incline on the treadmill actually simulates downhill running, which can put a tremendous strain on your knees and patellar tendon, especially if you have a pre-existing injury. Your muscles have to work harder to control your movements when going downhill so you don’t fall, and too much of this ‘eccentric strain’ can cause overuse injuries.” So stick with the just right incline to still get those steps in.

Equally as important as your step count is your VO2 max—here’s what that is. You can also try sprint interval training, which is like HIIT but way, way faster.