If there’s one accessory in particular that’ll get your fitness game on fleek, it’s the heart rate monitor. Not to knock colorful headbands and punny tank tops (because we’re all for a little fitness flair!), but these gadgets go beyond the cosmetic and may help your overall fitness.

Case in point: Using a heart rate monitor may help you find your running sweet spot (aka your ideal training pace) and prevent overtraining. (More on that below.) Plus, gadgets that monitor heart rate are relatively affordable compared to other schmancy fitness trackers, so there’s plenty of value. Best of all, it’s pretty easy to use: Simply strap the heart rate monitor on, connect it to an app or a watch (the monitors themselves often won’t have displays) and get your sweat on. These days, there are even “strapless” heart rate monitors that pick up your pulse from your wrist.

And while you can technically use these tech toys during any workout, they’re especially useful during certain scenarios, says Jason Fitzgerald, an elite marathoner, running coach, and founder of Strength Running. Follow these five steps to get the most out of heart rate monitors.

1. Learn your max heart rate.

It may sound simple, but figuring out your max heart rate is actually tricky business—that whole 220-minus-your-age formula is really just an estimate. Heart rate monitors to the rescue! Fitzgerald recommends wearing the monitor during a 5K (if you’re a runner) or a HIIT session to get a better read on your max heart rate. The key to this strategy? Making sure you’re going at an all-out effort. The highest number your monitor records is likely your max heart rate, and that can help you gauge your heart rate range for other types of workouts. Once you have that number, you can put it to use in the following ways.

2. Find your “easy.”

Nope, we’re not talking about those lazy Sundays spent binge-watching House of Cards. As we’ve discovered, scheduling “easy” workouts is great for balancing your fitness and recovery. But for all the gung-ho guys and gals among us, it can be tough to tone it down. That’s where heart rate monitors come in.

“Wearing heart rate monitors on easy days is a good way to keep yourself honest and make sure your heart rate doesn’t go above what it should be,” Fitzgerald says. For runners in particular, these easy days are opportunities for a lil’ active recovery, to build endurance, and to get some extra miles in—but that only works if the run is, in fact, an easy one.

And though the heart rate in this scenario is a tough thing to calculate (depends on variables like your age and fitness level), it’s likely going to feel super slow—Fitzgerald says most runners will want to keep their BPMs in the 140s or less, and some suggest sticking to 65 to 70 percent of your max heart rate during these recovery runs. Just remember the goal is to be in control, comfortable, and at a pace that’s conversational, Fitzgerald suggests.

3. Go long.

To keep on keepin’ on with any aerobic exercise (and to see improvements in performance), you’ve got to build your endurance. And a heart rate monitor can help you do just that during those longer bouts of exercise. Beginners will want to stick to 50 to 65 percent of their maximum heart rate during endurance training, while intermediate-level people should shoot for 60 to 75 percent, and experienced exercisers should aim for the 70 to 85 percent range.

4. Try for tempo.

Tempo workouts are a runner’s secret weapon behind being able to go faster for longerThe influence of training and mental skills preparation on injury incidence and performance in marathon runners. Hamstra-Wright K.L., Columbe-Lilley J.E., Kim H., et al. Journal of Strength and Conditioning Research. 013 Oct;27(10):2828-35.. By training the body to use the oxygen it receives more efficiently, tempo training helps you boost your lactate threshold (aka the point when your body starts to feel wiped out—cueing the burning-muscle sensation). The caveat: If you go too slow, you’re not going to reap these benefits.

It can be tricky to determine how fast your ticker should beat during tempo training—but the goal is roughly 85 to 90 percent of your max heart rate, Fitzgerald says. You want to be sure that the pace is uncomfortable but still manageable—you’ll likely be maintaining this pace for 20 minutes or so. Ready to try a tempo run? Here are a few methods to try, but it can vary by training program and coach.

5. HIIT it up.

This fast-and-furious workout is quite the coup, with benefits including a boost in metabolism, amped-up endurance, and major fat-burning potential. The plan of action? First, prepare to work up a serious sweat. Then perform rounds of speed intervals (working at 80 to 95 percent of your max heart rate) and recovery intervals (working at 40 to 60 percent of max heart rate). Depending on the format of your workout, the speed portions can last anywhere from five seconds to eight minutes, with the recovery portions lasting equally as long (or even longer).

All that said, it’s worth noting that HIIT workouts are really effort-based workouts as opposed to heart rate-based ones, Fitzgerald says. Translation: You’re generally paying attention to achieving all-out effort instead of hitting a certain number on a heart rate monitor—though, hey, it never hurts to use the tools you have handy!

The Takeaway

Not every fitness gadget is worth the moolah, but heart rate monitors can help you level up your cardio—and keep you from slacking or hitting your training too hard. The key to making the most of it? Calculating your max heart rate. Once you’ve got that, you’re just an easy jog, tempo run, or HIIT workout away from a fitter and faster physique.