Thanks to the influx of fitness trackers on the market, it's never been easier to observe your exercise progress in real-time. These wearables can display your heart rate, step count, blood oxygen level, the calories you've burned, and some will even monitor the quality of your sleep.

We took a look at six of the most popular fitness trackers on Amazon—each of which has at least a 4.1-star rating and 3000 customer reviews—to narrow down the ones that are worth the money.

1. Fitbit Charge 4; $130


With over 49,000 reviews and a 4.5-star average, this Fitbit model is probably your best bet if you're looking for all-around quality. In addition to all the necessary fitness tracker features, you can also take advantage of a built-in GPS to map out your exact path and reach mileage goals. And once you hit your target heart rate during a workout, the device will let you know with a slight buzzing sensation, so you don't have to keep looking down at your wrist during a jog. You can sync this Fitbit to your phone to hear your Spotify playlists, track your sleep habits, and see your Sleep Score.

Buy it: Amazon

2. LETSCOM Fitness Tracker; $21


This fitness tracker wants to keep you motivated to have a better lifestyle. Not only does the LETSCOM monitor your heart rate and track your sleep, but it will also provide sedentary alerts to let you know if you’ve been inactive for too long. While you'll get your pick of fitness features, the device is set up to send and receive calls, text messages, and tweets to stay connected while you’re “off the grid” in nature.

Buy it: Amazon

3. YAMAY SmartWatch Fitness Tracker; $30-$36


For less than $40, YAMAY’s waterproof fitness tracker monitors your heart rate, sets times for workouts, and can teach you deep breathing techniques to help with stress. And instead of being abruptly woken up by a loud alarm, this tracker uses gentle vibrations to slowly get you out of bed without disturbing others.

Buy it: Amazon

4. Lintelek Fitness Tracker; $26


Though the Linteleck fitness tracker wants to help you build healthy habits by monitoring your heart rate, sleep, and physical activity, it also functions as a basic smartwatch (which isn't bad for $26). You can pair it with your Apple or Android phone so you can call, text, tweet, and check your calendar right on your wrist.

Buy it: Amazon

5. Xiaomi Mi Band 5 Smart Wristband; $33


Xiaomi's 1.1-inch band makes this one of the sleekest fitness wearables out there. There are more than 100 watch faces and 11 different exercise modes to choose from, including elliptical, indoor bike, and swimming workouts. This tracker also has a women’s health feature that will record and send a reminder about where you are in your cycle.

Buy it: Amazon

6. Garmin vívosmart 4; $98


Garmin is known for its GPS devices, but the vívosmart 4 does so much more. You can monitor your blood oxygen through the built-in Pulse Ox sensor, and you can get a read of your energy levels based on your sleep quality, activity, and heart rate variability. And thanks to the device's 24-hour stress monitor, you can also get reminders and timers for breathing exercises.

Buy it: Amazon

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