First there were FitBits, then came the Apple Watch, and nowadays, you’d be hard-pressed to walk into a New York City fitness studio without some acknowledgement that you can track just about every part of your workout. That’s especially true for tracking your heart rate in conjunction to how hard you’re pushing yourself in your workout, which is why heart rate monitors are the single best buy you can make to up your fitness game. It’s also why you’re about to see them as a central part of every. single. workout.

“Your heart rate is an amazing tool to showcase how your body’s reacting to the individual workout, and it’s a significant upgrade versus just going by ‘feel,’ which levels up the knowledge base around overtraining, lack of sleep, and other effects that aren’t recognized by the average fitness consumer,” says Joanna Stahl, trainer and founder of Go2Practice, who’s definitely noticed heart rate tracking dominate the wearables market. “Heart rate training is now incorporated into every personal tech platform from products like Suunto, Garmin, Polar, and has spread into mainstream products like Fitbit and Apple Watches—it’s on the rise from a health tech perspective, and there’s no doubt it’s making the average health-minded consumer smarter and more aware of their bodies and heart-related issues.”

“There’s no doubt it’s making the average health-minded consumer smarter and more aware of their bodies and heart-related issues.” —Joanna Stahl

Of course it’s always been beneficial to measure your heart rate for your overall health, but it used to be something that was used as a diagnostic tool by doctors, and now it’s leveling up your workouts. “The data is easily available, it makes you a better athlete, creates awareness and intensity around your workouts, and showcases your results to review, be proud of, and grow from,” says Stahl.

Some workouts specifically call for max heart rates or intervals between higher and lower heart rates (HIIT!), so tracking your heart allows you to literally see how you’re doing and whether you’re in the targeted heart rate zone for peak benefits. “Heart rate training is imperative for results from HIIT training to make those intervals and intensities work properly,” says Stahl.

Orangetheory, the uber-popular HIIT studio, has been in on the heart rate tracking idea since they began—in each class, everyone gets a heart rate monitor so they can stay in a certain “zone” of an ideal heart rate exertion. Now, AKT, celebrity trainer Anna Kaiser’s studio, also incorporates heart rate monitors, and they’re being updated this November to be a central point in the workout. Kaiser tells me that you can link your heart rate monitor to your AKT App to keep track of everything as you sweat, which is ideal for goal-based training and a more accurate indicator of performance. “It also helps prevent plateauing in training programs, and creates awareness of your intensity,” she says.

As Stahl points out to me, knowledge is power. “As more and more people wear their monitors and tracking devices to workouts and are educated on how training ultimately effects heart function, we’ll all get a bit smarter and healthier in the process,” she says. In a sense: Tracking your heart rate means you’ll never miss a beat on your wellness journey.

Oh yeah, also you can track your bowel movements for better health (cool!), and your fertility (of course). Nothing cannot be tracked.