Fitness isn't just about the amount you exercise, it's also about the intensity of that exercise. A heart rate monitor (HRM) is your pacer, telling you when to speed up or slow down to achieve results. To select the best model for you, consider two factors:
- Monitor Type: Most monitors use sensors located on a chest strap or your wrist. Heart rate monitors with chest straps are the most accurate. Wrist-only heart rate monitors can be more convenient.
- Monitor Features: The most expensive models do everything imaginable. We highlight key features below, and devices are constantly adding new functionality.
This article also offers advice on how to use an HRM and who should use one:
- Heart rate target zones are the critical data an HRM provides. We explain how to calculate yours for your age and for your fitness goals.
- User notes highlights how an HRM can benefit a variety of people, from those focusing on weight loss to those focusing on peak performance.
For additional help deciding whether a heart rate monitor is the right tool for you, see our Expert Advice articles How to Choose a Fitness Tracker.
Types of Heart Rate Monitors
Chest-strap HRMs: A wireless sensor on a chest strap detects your pulse electronically and sends that data to a wristwatch-style receiver, which displays your heart rate. Once you get used to the routine of putting on the heart rate monitor chest strap and working out with it on, a strap will provide the most accurate heart-rate results. Some can also broadcast to GPS cycling computers. This gives the advantage of not having to look at your watch as you ride. It also integrates with fitness data through Strava, Garmin Connect and other fitness software platforms.
Wrist-based HRMs: An optical sensor built into the wrist unit's watchband or case back detects your pulse. Though heart rate monitor watches are slightly less accurate, wrist-based models avoid the discomfort and additional pre-workout fuss associated with chest straps. Wrist based HRMs can be worn 24/7 (except when charging) which helps with tracking heart rate at a more detailed level. But it also helps with recovery and sleep data. The more your device can read your heart rate, the more accurate your recovery times and sleep data are.
Heart Rate Monitor Features
Basic HRM models time your workout and give you continuous, average, high and low heart rate data, as well as the high, low and target heart rate reached during your workout. Many models can be partnered with a foot pod that attaches to your shoelaces to track your speed, distance and cadence.
Other models have GPS receiver capabilities to track speed and distance, also providing elevation and navigation functionality. The most advanced (pricey) models have an extensive and ever-growing array of features.
Target zones: Basic models offer up to 3 target zones; advanced models have from 3 to 6 target zones. With the capacity for multiple target zones, you can preprogram your heart rate monitor for a series of different workouts (e.g., endurance, aerobic and anaerobic variations). If your HRM offers only a single aerobic target zone, you'll need to reprogram it every time you want to change the exercise parameters.
Sport watch: Heart rate monitor watch models include features such as a clock, alarm, countdown timer and calendar.
Stopwatch and lap/split times: After each lap at a track or every mile on a marked-distance race course, hit the "Lap" button to see how your pace has changed throughout your workout or race (a.k.a. your "split").
Recovery heart rate mode: Tracks the time it takes your heart to return to its normal, resting rate. It's a good indicator of cardiovascular fitness and especially important if your workouts include sprints or interval training.
Time in target zone: Tracks the time you spend exercising within your target zone. Some zones and goals require more time than others.
Calorie counter: Estimates the calories burned during exercise. This can be especially handy if your workouts are part of a weight-loss program.
Speed and distance monitor: Calculates the speed and measures the distance covered in a particular workout. This is typically done via a GPS receiver for outdoor use or a foot pod for indoor use or use in an outdoor area with limited satellite reception. A foot pod uses an accelerometer to determine the length of each stride.
Digital interface: Connects your heart rate monitor to your home computer or smartphone so you can download training statistics for analysis, sharing and storage. This may be wireless or require a separate computer connection.
Tethering: Wirelessly pairs with your smartphone to allow wrist-top control of phone functions such as text messages, music, push notifications, fitness apps and social media—all without taking your phone out of a pocket or armband.
Fitness trainer: Provides alerts for intensity levels that fall above or below your chosen training zones.
Coded transmitter: Encrypts transmissions from the heart rate monitor chest strap sensor to the wrist unit to prevent crosstalk (signals from the wireless HRMs of others exercising around you).
Sport-specific features: These can include speed and cadence feedback for cyclists or pool-lap counters and stroke recognition for swimmers.
Battery replacement: Some HRM wrist receivers use consumer-replaceable or rechargeable batteries to simplify maintenance.
Heart Rate Target Zones
A key benefit of an HRM is that it helps you maintain the optimal heart rate target zone for your specific goal. Higher-end models inform you of this via a digital display and/or an audible tone.
The target zone is a percentage range based on your maximum heart rate (HR max). Various algorithms have been developed to calculate an HR max estimate. The classic 220 - your age formula is now considered inaccurate for older people. A revised formula, 208 - 0.7 x your age, is better.
The American Heart Association chart below offers a broad overview of HR values for target training zones and average HR max values. For more details on calculating your personal HR max and how training zones work, read How to Train Using Heart Rate Zones. (It's always best to have a stress test under a physician's supervision to determine your actual HR max.)
| Range of Target HR Zones (50-85% of HR Max) | Average HR Max (100%) | |
|---|---|---|
| Age | Beats/minute | Beats/minute |
| 20 | 100-170 | 200 |
| 30 | 95-162 | 190 |
| 35 | 93-157 | 185 |
| 40 | 90-153 | 180 |
| 45 | 88-149 | 175 |
| 50 | 85-145 | 170 |
| 55 | 83-140 | 165 |
| 60 | 80-136 | 160 |
| 65 | 78-132 | 155 |
| 70 | 75-128 | 150 |
Who Should Use a Heart Rate Monitor?
Note: Before initiating any exercise program, consult a physician to design a program that is well suited for your goals and current conditioning.
Joggers and walkers: Recreational exercisers can benefit from heart rate monitors in the same way elite athletes do. By aiming for fat-burning and aerobic target zones on your HRM, you can get more out of your exercise time.
Runners: A heart rate monitor can keep you in your peak target zone on intense training days and at your aerobic base during easier sessions.
Cyclists: An HRM can track your training performance during endurance, tempo and interval rides, whether you bike on a road, trail or stationary trainer. Some models deliver more feedback via a cadence sensor or foot pod.
Triathletes: In addition to cyclist-related features, some HRMs monitor swim-related data like distance, pace, stroke type/count and number of pool lengths.
Hikers, climbers and skiers: Use a heart rate monitor to condition more effectively for a peak ascent.
Weight-loss participants: HRMs help with regular exercise and a sustainable dietary regimen. Most display calories burned during a workout; many can help target your exercise for maximum fat burning.
Injury-rehabilitation patients: Real-time feedback makes HRMs valuable for patients recovering from an injury or an illness, including a cardiac incident. Such data can help ensure that your gradual return to full strength and endurance proceeds safely and steadily.