Never mind the workouts you crush on the regular. The real fitness challenge: snagging a sports bra you actually like. Between the inconsistent and confusing sizing system to the gymnastics you have to do to get one on your body, it’s no wonder finding The One ends up being a not-so-stellar experience.

sports bra: lululemon enlite

Women often compromise on how a sports bra looks, feels, or performs, says Alexandra Plante, Whitespace innovation product manager for Lululemon (Whitespace is the brand’s research and development lab, and Plante worked on the team that put two years of research into the new Enlite bra, which was designed with these concerns in mind). One major obstacle for female workout warriors? Figuring out the right fit.

“Fit is incredibly important when choosing your sports bra,” Plante says. Comfort is key here. One rule of thumb: “Nothing should be digging in, cutting into, or poking the breast, and your entire breast should be covered by fabric.”

While finding a great fit does come down to trial and error (they say you’ve got to kiss a lot of frogs), we gathered some intel that can help streamline the process.

Get an Expert Opinion

First of all, you might want to consider getting yourself fitted by an expert—especially if you’re overwhelmed by all the options or feel like your body’s recently changed. “Bra fit between styles and across brands can vary,” Plante confirms. And what works for one woman isn’t necessarily going to work for the next. Add in the “sister size” situation (which Plante says is really just two sizes with the least amount of difference in band and cup sizing—for example, a 34B and a 32C), and you’ve got a lot to deal with in the dressing room.

In-store fit experts will not only measure you for size but can also help pick out options that suit your lifestyle and fitness goals, adds Candice Smith, chief lingerie stylist at Rigby & Peller. Not your jam? No worries—many brands have online fit and measuring guides and even quizzes that can point you in the right direction.

One other thing important to note: While women with smaller busts have a little more wiggle room in how much support they need (fuller breasts have heavier breast tissue that requires extra backup), all women need good support, Smith stresses.

See, breasts move much more than you might realize. Research shows they bounce up and down (as much as 21 centimeters!) and also move in a figure-eight pattern.Breast displacement in three dimensions during the walking and running gait cycles. Scurr J, White J, Hedger W. Journal of applied biomechanics, 2010, Feb.;25(4):1065-8483. For some, movement equals pain: Scientists estimate that more than half of all women feel breast pain while working out. To make matters worse, not having enough support may impact performance; one study suggests it changes the way you run.The effect of breast support on kinetics during overground running performance. White JL, Scurr JC, Smith NA. Ergonomics, 2009, Jul.;52(4):0014-0139. That’s no bueno. Plus, unrestricted motion can damage the breast tissue, Smith adds.

The Anatomy of a Sports Bra

The key players in any sports bra? The straps, the cups, and the band.

The band: Think of it as your bra’s secret source of power—it’s actually where the majority of support comes from, Smith says. Plus, if it’s doing its job properly, it’s going to prevent unnecessary strain on the straps (and pain for your shoulders). And—bonus!—if the band happens to have a clasp closure, it makes it way easier to get the bra on and off, and the ability to adjust can yield a more customized fit.

  • Signs you’ve got a good fit: “The band should be parallel to the ground and not hiking up in the back,” Plante says.

The cups: Sports bras fall into one of three categories: compression, encapsulation, or a combo of the two. The former squishes your boobs into your body, creating a flatter, bandeau-like look (some may say uniboob). Although it streamlines the package, it doesn’t do a lot to support your boobs, Smith warns. These are probably best for low-impact workouts.

As for encapsulation sports bras, think of them as souped-up versions of your everyday bra; their design features individual cups that separate the breasts and completely cover each one, may include an underwire (which is really just for shaping purposes), and typically has hook-and-eye closures on the band. Smith highly recommends them for most workouts.

  • Signs you’ve got a good fit: Both of your breasts are entirely—and comfortably—covered. “If you’re spilling out, the bra is cutting into you, and it won’t do anything for breast movement in those unsupported areas,” Plante explains.

The straps: The skinnier the straps (and the more intricate the design), the less support you’ll get, Smith says. Thicker straps generally reduce the tension placed on your shoulders. This is an important point, since sports bras have gotten a lot more stylish, with many featuring unique strappy designs made for showing off.

  • Signs you’ve got a good fit: They stay put on your shoulders without digging into or pinching your skin, Plante says.

Finally, you also want to consider the fabric and other design elements. If the words moisture wicking appear on the label and you see ventilation panels (mesh or breathable fabric sections), know that the bra’s designed to be lightweight—and keep you cool, calm, and collected throughout every workout.