It’s common sense, but science backs it up: You’re likely to work out longer and more often—and enjoy it more if you exercise with someone else versus solo.

Well, most of the time, anyway. As with most bold claims, this comes with some fine print. As much as a great workout partner or exercise group can enhance your workout, the wrong one can hold you back or even sabotage it. Here’s how to choose the right one.

Don’t Swipe Right

First, how not to go about it: Skip the apps designed for this sort of thing. There’s Gymder, which alerts you to other app users nearby, whether across the gym or across town, and lets you view their profile—which basically means check out the selfie they uploaded. Meetup and Bvddy (no, that’s not a typo) can connect you with people who enjoy the same activities. But using these apps is like shopping for the perfect pair of jeans at a thrift store. You have to sift through a lot of wrongs—some of them a bit funky-smelling—before you may or may not find the “right.”

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Keep Your Radar On

If you avoid apps (and you should), you’ll need to choose from the people already in your sphere. Is there anyone who seems like-minded in their desire to exercise? Or who seems to enjoy the same activities you do? If a friend mentions wanting to run a race or shed a few pounds, your antennae should perk up. Or is there someone at the gym who also seems to be using the same equipment you are? If you find a possible candidate, the two (or more) of you should consider the following questions:

  • Do you have similar goals? It will likely be a bust if one of you wants to run a marathon and the other just wants to drop 5 pounds.
  • Are your schedules compatible? Night owls and morning larks don’t always mix.
  • How intense are you? If your friend is into leisurely strolls and you’re the CrossFit type, well, you can see where that’s going.
  • Do your fitness levels mesh? You don’t have to be exactly the same—a lot of workouts can be modified to accommodate multiple fitness levels. In fact, you should consider choosing someone slightly more fit than you are, because it can push you to work harder, as multiple studies indicate—including Kansas State University research that found people exercised up to 200 percent harder when working out with someone who they perceived as more fit than they were.

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Don’t Limit Yourself

All this compatibility talk may make the hunt for a workout partner sound a lot like dating. But it’s not, so consider connecting with more than one workout partner—maybe you’ll have a weekday gym buddy and a different friend who you walk or hike with on the weekends. And remember the goal is fitness, not lifelong commitment, so you and your workout partner should reassess every few months to see if it’s still a good fit. As we said at the beginning, working out with someone else is good common sense, but so is recognizing when it isn’t.

Kellee Katagi is one of those strange souls who actually enjoys working out for the sake of working out. She’s spent most of her 20-plus-year writing and editing career covering fitness, nutrition and travel, as well as outdoor sports ranging from skiing to spelunking to street luge (yes, that’s a thing).