Keeping track of your heart rate while you exercise is beneficial for a number of reasons. Perhaps most importantly, it helps you recognize if your heart rate is too high, potentially putting you at risk of a heart attack or stroke. But it can also tell you if your heart is beating too slow, which means that you need to pick up the pace if you want to get better results.So, which fitness trackers are the best when it comes to this particular feature? Here are three wrist-based to consider: chargeHR by fitbitThe chargeHR is a heart rate monitor that flashes your heart rate on its little screen, making it super simple to tell when you’re “in the zone.” In addition to keeping track of your heart beats, it also tallies your workouts, calories burned, steps taken, and more. It even monitors your sleep and can act as an alarm. Polar FT60Another great wrist-based heart rate tracker is the Polar FT60. Not only will it tell you when your heart rate is right where you want it to be, but it can also create a training program for you based on your goals, even giving you feedback about how you’re doing along the way. It’s like a personal trainer and heart rate monitor all in one. Forerunner 225 by GarminGarmin’s Forerunner 225 not only gives you your actual heart rate, but it also shows you where it is on an easy-to-read scale so you can always tell how far you are from other fat burning zones. The Forerunner also keeps track of distance and pace, both indoors and out, making it a great tool no matter what your workout.If you have a heart rate monitor, which one is it and what do you think of it? Feel free to share your comments below!