Best Heart Rate Monitors for Running of 2023

Having a heart rate monitor while running can help you reach your fitness goals by collecting data and making it easier to pace your runs.

Training with a heart rate monitor can allow you to collect important data and pace your runs correctly. Photo: iRunFar/Eszter Horanyi

If you are a strictly recreational runner or a seasoned professional, having the best heart rate monitor for running could help you improve your fitness. Whether that means being able to run at a faster pace, having the strength to run the hills instead of hiking, or being able to hold a conversation with running buddies without feeling out of breath, there is one measurement that can get to the heart (pun intended) of your fitness goals. You guessed it, heart rate!

Heart rate is one of the most valuable training metrics for athletes of all types. Monitoring your heart rate while active and at rest gives a lot of insight into your fitness, recovery, and day-to-day health. Combining data such as resting heart rate, heart rate during activity, and heart rate variability with running pace and perceived exertion will give you great information about fitness trends and is very valuable when gearing up for a big event.

Check out our guide below for more information on the types of heart rate monitors available and tips on choosing the best one for running that fits your needs and budget.

For more background information, see our buying advice, testing methodology, and frequently asked questions below the picks.

Best Overall Chest Strap Heart Rate Monitor for Running: Polar H10Best Chest Strap Heart Rate Monitor for Running – Runner-Up: Garmin HRM-Pro PlusBest Arm Strap Heart Rate Monitor for Running: Scosche Rhythm24Best Arm Strap Heart Rate Monitor for Running – Runner-Up: Polar Verity SenseBest GPS Watch Heart Rate Monitor: Garmin fēnix 7 – Solar EditionBest GPS Watch Heart Rate Monitor – Runner-Up: Apple Watch UltraOther Great Heart Rate Monitors for Running: Myzone MZ-Switch

The iRunFar team named the Polar H10 the best heart rate monitor chest strap. Photo: iRunFar/Eszter Horanyi

Pros:

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The Polar H10 heart rate sensor is an easy-to-use and reliable monitor that is a favorite among many. The ECG monitor is very accurate, and the unit itself is slim and lightweight. It is paired with the most comfortable strap that we tested. The material is soft and stretchy, and the flat buckle closure did not dig in or cause chafing. In addition to the rubberized ECG leads on the front, sections of silicone dots are along the strap to keep it in place. We didn’t notice any slipping with movement. The monitor uses a CR2025 battery and boasts an impressive 400-hour battery life. It is water-resistant to 30 meters and can also be used in normal swimming conditions.

The monitor connects to devices using both ANT+ and Bluetooth. We found it to connect quickly and easily to our Garmin fēnix 7 GPS watch and an iPhone, and pairing it with other apps was a breeze. The monitor itself has internal memory and will save one activity to download later. This memory was less than some other monitors we tested. We found the Polar app situation a little confusing as there are two: Polar Beat and Polar Flow. It wasn’t immediately obvious which one should be used, but we used Polar Flow, and this worked well for firmware updates and checking settings. It can also be used to record activities.

Sensor Type: ECG | Battery Type: CR2025 lithium | Battery Life: 400 hours | Strap Sizes: XS-S (58-71 centimeters/ 23-28 inches), M-XXL (67-95 centimeters/ 26-37 inches), XXXL (82-140 centimeters/ 32-55 inches) | Connectivity: ANT+, Bluetooth (2 connections)

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The Garmin HRM-Pro Plus is an accurate ECG chest strap monitor with additional metric tracking features, making it an excellent choice for the data-loving runners in our midst. This heart rate monitor connects to equipment and devices using both ANT+ and Bluetooth, with the capability for three Bluetooth connections. The strap was not the most comfortable of the bunch, but it functioned well. A small tag covers the clasp area to prevent it from digging into the skin, which we liked. The unit runs off of a standard CR 2032 battery with an estimated battery life of 360 hours. The battery is easily replaceable, and this model has a tool-free battery door that can be twisted open, which is a small but thoughtful detail. The monitor device is a little thicker than others tested and stuck out enough to get in the way of a sports bra band.

For Garmin users, this strap couldn’t be easier to use. It easily paired with our Garmin fēnix 7 and the Garmin Connect app. In addition to heart rate recording, it can store data with onboard memory and capture running dynamics such as vertical oscillation, ground contact time, and stride length. It also has an indoor running mode to transmit pace and distance on indoor tracks and treadmills, though you will need a compatible device to take advantage of these features.

Sensor Type: ECG | Battery Type: CR 2032 | Battery Life: 360 hours | Strap Sizes: 23.5-42 inches (60–106 centimeters) Optional strap extender: 23.5-56 inches (60–142 centimeters) | Connectivity: ANT+ (unlimited), Bluetooth (3 connections)

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The Scosche Rhythm24 earned top marks among the optical heart rate monitors tested. The optical monitor uses green and yellow lights to improve accuracy across different skin tones. Most optical heart rate sensors only use green light. The band itself is designed to be worn on the upper forearm. Depending on your arm size, there is enough stretch to be used on the bicep area as well, and it functioned well in both places for our tester. While optical monitors are not as precise as ECG monitors, this one performed very well at rest and during some warm weather running and hiking.

This heart rate monitor is a little bigger than others we tested but was still comfortable to wear. It has some nice extra features, including recording up to 13 hours of activity without your phone or watch that can be downloaded later. The exterior of the monitor has visible color-coded lights that indicate your heart rate zone. The device is rechargeable and has a battery life of 24 hours, and a green battery indicator light is visible on its exterior. The ANT+ and Bluetooth connectivity were easy to sync to a GPS watch and smartphone, and the device syncs quickly to the Scosche Rhythm Sync app for updates and to sync activities. It also easily connected to third-party apps, such as Strava. The app offers multiple activity modes, and the monitor is waterproof down to 10 feet for swimming.

Sensor Type: Optical, green, and yellow light | Battery Type: Rechargeable with specific device charger | Battery Life: 24 hours | Strap Sizes: Standard band 7-12.5 inches (18-32 centimeters), XL band 8.25 – 15.25 inches (21-39 centimeters) | Connectivity: ANT+, Bluetooth

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The Polar Verity Sense is an armband heart rate monitor that packs a lot of features into a tiny package. Measuring just a hair under three by one centimeters (1 x 0.4 inches), the monitor “pod” itself is barely larger than the coin batteries powering the chest straps mentioned above. This monitor uses green lights on the sensor to detect and monitor heart rate. The unit is clicked into a plastic holder on an elastic strap that can be worn on the forearm or upper arm and also has a unique holster that can attach to goggles at the temple for heart rate data while swimming. We found the strap to be very comfortable on both arm positions and easy to adjust, and our heart rate data was pretty accurate during walking, running, weight training, and cycling activities. The battery life of this rechargeable monitor is an impressive 30 hours.

Connectivity to devices and apps was easy using both ANT+ and Bluetooth, and this monitor also connects to the Polar apps. One nice feature is its ability to transmit to devices over a longer range. You can broadcast to a device up to 150 meters away, so you can start a swim or gym workout on your device and transmit your heart rate data to your phone app directly without having to save and download it later. Don’t want to have your phone or watch nearby? The unit also has onboard memory to record and download activities later as well. For those looking for a compact, lightweight optical monitor or who are frequent swimmers, this is an excellent heart rate monitor choice.

Sensor Type: Optical, green light | Battery Type: Rechargeable with specific device charger | Battery Life: 30 hours | Strap Sizes: 23-32 centimeters (9-12.5 inches) | Connectivity: ANT+, Bluetooth (2 connections)

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The Garmin fēnix7 – Solar Edition is a popular GPS running watch that was also the top pick in iRunFar’s best GPS watch buyer’s guide. As far as heart rate monitoring goes, the watch uses a green light optical sensor to track heart rate, providing data every second for accurate daily heart rate data. The watch also provides heart rate variability data, either with a spot recording or by measuring overnight and generating a report in the Garmin Connect app.

As with all optical monitors worn on the wrist, the heart rate data is less accurate during activity than that provided by an ECG chest strap. The wrist-based heart rate data obtained from GPS and smart watches at rest are much more accurate than those collected in motion. If you aren’t super concerned about the accuracy of heart rate information, the wrist monitor on this watch will give decent info about your heart rate trends during activity. I have found mine to be fairly accurate overall in its averages, but viewing the graph shows some spikes and dips that are certainly due to motion artifacts. If you are seeking more precise heart rate data, pairing this watch with a chest strap monitor for use during activity is very easy.

While the battery life of this watch is solid by itself, the solar charging capabilities extend its use between wall charges significantly, especially if you’re running in sunny locations.

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The Apple Watch Ultra packs a lot of features and data collection into a small package and is popular among runners who want a smartwatch with GPS capability, long battery life, and health-tracking information all in one. It was named the best smartwatch for running in the iRunFar best GPS watches guide.

This watch edges out other competitors in the category for its heart rate tracking capabilities. It uses a green LED light optical monitor on the wrist to track heart rate 24/7 and provides both resting and in-activity heart rate data. The watch also provides heart rate variability information. These sensors work great at rest, and several different apps can be used to analyze the information obtained from the watch. In addition to tracking heart rate, the watch provides ECG monitoring, a feature not found on most GPS watches. One caveat is that the ECG monitoring is only designed to detect a normal rhythm or atrial fibrillation. This is valuable but limited information.

As with all optical monitors, moisture, skin tone, and movement impact the device’s accuracy. The degradation in heart rate data from arm movement is the worst with wrist monitors, so while watches like this one provide great data on a continuous day-to-day basis, the information obtained during running will not be as accurate as that from chest straps or even upper arm optical monitors. That being said, heart rate monitoring is certainly not the primary reason to purchase an Apple Watch, but this device will provide quality heart rate data for its users. The addition of ECG monitoring is a plus for this device.

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The Myzone MZ-Switch offers the best chest strap ECG heart rate and armband monitors. The module can record heart rate using ECG by attaching to the included chest strap with two snaps. It also has a green light optical sensor which can be used on the wrist, forearm, or upper arm. Our tester found the chest and upper arm straps to be comfortable, but the wrist strap has scratchier nylon. The forearm strap has a Velcro attachment that is easy to adjust while wearing but may wear out faster with long-term use.

We found both sensors to be very accurate, and according to Myzone’s site, the ECG sensor boasts 99.4% accuracy, while the optical monitor is 95% accurate. The optical monitor has color-coded lights that are easy to see that correspond to your heart rate zone so that you can keep track of your effort without having to look at a phone or watch. Like our other picks, the unit connects to devices using ANT+ and Bluetooth and has its own smartphone app to view settings and activities recorded directly on the monitor using its onboard memory.Battery life is reported to be three to six months per charge by MyZone but doesn’t really specify what type of use that translates to.

Sensor Type: ECG and optical, green light | Battery Type: Rechargeable with specific device charger | Battery Life: 3 to 6 months | Strap Sizes: Chest Strap: Small (53-69 centimeters / 21-27 inches), Standard (61-86 centimeters / 24-34 inches), and Large (69-102 centimeters / 27-40 inches) | Connectivity: ANT+, Bluetooth (2 connections)

Chest Strap Versus Arm or Wrist Strap

The three most common types of heart rate monitors (HRM) for running are chest straps, arm straps worn on the forearm or upper arm, and wrist monitors, which are either a watch or a wrist strap.

When it comes to accuracy, the best heart rate monitor for running is a chest strap, like the Polar H10. They use electrocardiogram monitoring, commonly referred to as ECG or EKG, to detect and track your heartbeat. A strap encircles the chest around the lower rib with two electrode patches on each side that contact the skin and sense your heart’s electrical conduction to record your heart rate. The chest strap heart rate monitor is less likely to have data errors from moisture or movement as they are made to fit tightly and don’t shift with arm swing.

Arm and wrist strap monitors, including the Polar Verity Sense and the Garmin fēnix 7 – Solar Edition, use optical monitors to record heart rate. LED lights mounted on a sensor detect changes in blood flow in the blood vessels in the arm. This small change in volume in the vessels as blood pumps out of the heart correlates with your heartbeat and can be measured. These HRMs are easy to take on and off and can be comfortably worn all day, making them a good choice for sleep tracking and all-day heart rate monitoring. Optical sensors on the wrist and arm are more likely to be susceptible to erroneous readings from arm swing during activities like running that can cause the sensor to move or slip.

Compatibility with Devices

The best heart rate monitors for running use two types of technology to connect to devices such as watches, smartphones, or fitness equipment: Bluetooth or ANT+.

ANT+ (Adaptive Network Technology) is a low-power wireless network technology that allows sensors from different manufacturers to communicate and share data with different devices. Heart rate monitors utilizing ANT+ technology, such as the Garmin HRM-Pro Plus, Polar H10, and Myzone MZ-Switch, can connect to multiple devices simultaneously using ANT+ without interference. This means you can use your heart rate monitor to connect to your fitness watch and fitness equipment, such as a treadmill or cycling computer, simultaneously to track your heart rate during activities.

Bluetooth is another method used to connect heart rate monitors to other electronics. This connects like you would connect other Bluetooth devices, such as wireless headphones. Bluetooth is most commonly used to connect an HRM to a smartphone app, such as Polar, Garmin Connect, or Strava, which is then used to display your heart rate or download activity data from the heart rate monitor module.

The Myzone MZ-Switch has a comfortable strap and can be worn with a forearm or chest strap. Photo: iRunFar/Eszter Horanyi

Optical Versus ECG Monitoring and Accuracy Expectations

When choosing the best heart rate monitor, ECG monitoring is the gold standard for accurate heart rate recording. Chest heart rate straps, like the Garmin HRM-Pro Plus, use a simplified version of the ECG monitoring you can find in a hospital or doctor’s office and are very reliable. The ECG monitor uses electrodes to detect the electrical signals that make up each heartbeat. In the case of a heart rate monitor chest strap, two rubberized areas on the strap that contact your skin measure the electrical signal, and the unit can count the number of beats each minute. As long as the chest strap electrodes maintain good contact with your skin, this heart rate tracking method is extremely accurate and not significantly impacted by body movement or moisture. A number of research articles have confirmed this, including one by Pasadyn et al. (2019), who found that a Polar H7 chest strap heart rate monitor had the most accuracy over optical heart rate monitors when compared with a traditional three-lead ECG during treadmill running.

Optical heart rate recording uses a light source — often LEDs — that transmits light through the skin to the blood vessels. Optical heart rate monitors for sports are often worn on the wrist, forearm, or upper arm and measure the blood flow in the large blood vessels in your arm. These measurements are translated into a waveform representing your heartbeat, and an algorithm calculates the beats per minute. These recordings are very accurate at rest but are susceptible to factors such as device fit and motion artifacts that make them less reliable during intense exercise. This issue worsens, particularly if the device is not tightly fitted and there is a lot of arm movement, such as running. GPS watches, like the Garmin fēnix 7 – Solar Edition, use optical heart rate monitors to track heart rate, though they can be connected to chest straps as well for more accurate data.

Activity Use

The accuracy and comfort of even the best heart rate monitor for running will be impacted by your activities while wearing it. As mentioned above, the accuracy of optical heart rate monitors worn on the wrist is much less when the arm moves. The arm swings and movements associated with running, swimming, or intense cross-training, such as Crossfit or kettlebell workouts, will likely make your heart rate data less accurate and useful. In addition, wearing a watch with heart rate monitoring on the wrist while doing weight workouts runs the risk of the watch being struck by a piece of equipment and being damaged. A chest strap that records data during activities, such as the Garmin HRM-Pro Plus or the Polar H10, is a good choice for activities that don’t require the GPS of a watch, as you can download your activity after you are finished. Another option for those who don’t like the feel of chest straps is a forearm or bicep optical monitor, like the Scosche Rhythm24, Polar Verity Sense, or Myzone MZ-Switch.

In addition to movement, debris between the skin and the optical sensor will also interfere with readings. For example, mud, sand, or sunscreen could cause errors in optical heart rate readings. Navalata et al. (2020) found that the accuracy of a chest strap heart rate monitor was superior to multiple types of optical sensors in a trail running setting.

Activities with less or slower arm and hand motion, like cycling, walking, or hiking, are better suited for wrist heart rate monitors. Wrist monitors are more comfortable for daily wear since you won’t have to worry about fitting an armband monitor under your sleeve or dealing with the more constrictive feeling of a chest strap.

The Scosche Rhythm24 uses two different colors of light to provide a more accurate optical heart rate measurement. Photo: iRunFar/Eszter Horanyi

Types of Use

One of the most important things to consider when choosing the best heart rate monitor for running and life is how you plan to use it. Not all heart rate monitors have the capability to provide constant readings. Most arm and chest straps we tested only record heart rate during activities.

We prefer a watch-based optical heart rate monitor such as the Garmin fēnix 7 – Solar Edition or Apple Watch Ultra for daily wear. These are comfortable and serve multiple functions in addition to heart rate monitoring. In the case of the Apple Watch, there is built-in ECG capability that can detect atrial fibrillation, a particular abnormal heart rhythm. This technology will likely be available in other GPS watches in the near future. If you are already diagnosed with or at risk for atrial fibrillation, this is an excellent choice for a GPS watch and health tracker that can also alert you to an abnormal heart rate.

As we mentioned above, chest strap ECG heart rate monitors will be the most accurate during all types of activity. Many of these have built-in memory to store data directly on the monitor to be downloaded later. Upper arm optical heart rate straps are a good compromise for those that want accurate heart rate readings but find chest straps uncomfortable as they have less variation with movement than wrist monitors.

Comfort

Comfort is an entirely subjective matter when it comes to running gear, and heart rate monitors are no exception. The strap materials, size of the heart rate monitor device itself, clasps, adjustability, and wear position will all impact comfort. Our team found the Polar H10 more comfortable than many other heart rate chest straps tested.

Comfort is one area where the chest strap heart rate monitors tend to fare worse than their counterparts. Many runners don’t like the sensation of constriction around their lower chest from the chest strap. Wet and hot conditions can lead to chafing or slipping of the device, especially for those with a higher sweat rate. Runners who wear sports bras, especially higher support bras, often find chest straps more uncomfortable as they add another layer of compression around the chest. Most straps come in a range of sizes, but people on the high or low end of the size range may have trouble getting a good fit. The small size of the Polar Verity Sense made it a favorite with our testers.

Arm and wrist strap heart rate monitors are a little more comfortable and easier to adjust while wearing than chest straps, and for many people, they are the right choice for the best heart rate monitor for running. Arm strap optical heart rate monitors can be worn on the forearm or upper arm to further dial in comfort and fit runners with a variety of arm sizes. If you have issues with swelling of the hands or fingers during long efforts, having a constricting band around the arm or wrist may become uncomfortable or even cause some numbness or tingling. Usually, loosening the strap will help reduce pressure and alleviate this, but you may need to remove the band entirely if you develop these symptoms and they do not go away right away with loosening the strap.

Cost

As with many types of gear, heart rate monitors have a range of price points. Our research found the lowest price for a basic heart rate monitor with Bluetooth and ANT+ to be around $30. On the other end of the spectrum, some monitors cost nearly $600 that provide continuous ECG monitoring and additional metrics that, while interesting from a data perspective, are probably unnecessary for most runners. For most people, the best heart rate monitor for running isn’t necessarily the most expensive. We found that most well-equipped and reliable ECG chest strap and optical arm strap heart rate monitors fall into the $70 to $100 range. While not cheap, these will be a solid investment that will last for many years, with only the occasional battery change or strap swap needed to keep them going. Many of the more expensive options, including the $800 Garmin fēnix7 – Solar Edition, provide many other features besides heart rate monitoring.

The most accurate option is ECG heart rate monitors like the Garmin HRM-Pro Plus and the Polar H10. Photo: iRunFar/Eszter Horanyi

The Garmin HRM-Pro Plus comes with a variety of extra data collection options. Photo: iRunFar/Eszter Horanyi

We began searching for the best heart rate monitor for running by researching the types and models geared toward sports that are available today. We narrowed our selection of the best offerings to test from this list. We spent several months using both chest strap and arm strap optical heart rate monitors in a variety of conditions to compare their comfort, ease of use, durability, and accuracy. From this, we chose our top picks across these categories.

Please note that product models are routinely discontinued in the running world, while new ones frequently come to market. At the same time, we here at iRunFar often keep using our top picks in our daily running … they’re our top picks, after all! Sometimes that continued use results in uncovering product failures. With all this — product discontinuations, product introductions, and product failures — in mind, we routinely update our buyer’s guides based on past and ongoing testing and research by our authors and editorial team. While these updates can appear to be us pushing the newest product, it’s anything but that. When we update any buyer’s guide, most products will likely remain the same. That matches our goal: to get you in the best gear you’ll be using for a long time.

Why should I use a heart rate monitor?

Monitoring heart rate has a wide variety of applications when it comes to running and fitness. Heart rate monitors can be worn all day or only during activity to monitor a variety of metrics that give insight into your health, fitness, and training readiness. Heart rate monitors for running can be used to record, track, and trend resting heart rate, heart rate variability, and heart rate or heart rate zone during training.

Keeping track of resting heart rate and heart rate variability over time can be a good indicator of overall fitness and changes in fitness. A heart rate measuring watch, like the Garmin fēnix 7 – Solar Edition, can make it easy to track this metric. Changes in these measurements can signify problems such as dehydration, illness, or poor recovery. Monitoring these numbers and noting any upward or downward trends can help to decide how hard to push in workouts or whether you need a little more rest. Using a heart rate monitor during training sessions can ensure you stay within the prescribed workout zone to avoid going too hard or too easy and overexerting or missing out on fitness gains.

What is a heart rate zone?

Heart rate zones are target training zones based on a percentage of your maximum heart rate (MHR). To calculate and use heart rate zones for training, you first must calculate your MHR. The gold standard and most accurate way to determine this is through medically supervised testing in a sports physiology lab where you are monitored as you run on a treadmill with increasing speed until exhaustion. This type of test will provide your actual MHR and several other metrics like lactic threshold and VO2 Max that measure your body’s capability to use oxygen during exercise. For those who do not have access to or aren’t interested in this advanced testing, simple math equations give fairly accurate estimates.

The most basic and widely used way to estimate your MHR is to subtract your age from 220. If you are 40 years old, your MHR estimate would be 180 beats per minute. There are other equations, including the Tanaka (208 – 0.7 x age) and the Gulati (206 – 0.88 x age, for females), that can also be used (Abdelmoneim et al., 2015; Roy & McRory, 2015).

Once the maximum heart rate is established, you can calculate the percentages used for heart rate training zones. Most heart rate monitors and their associated apps and standalone fitness apps, including Polar, Garmin, Scosche, Wahoo, and Strava, will calculate all of this for you. You can then use these to guide your training. The Garmin fēnix 7 – Solar Edition and Apple Watch Ultra can display heart rate zones as part of your activity recording during exercise, and some of the heart rate monitors like the Myzone MZ-Switch and Scosche Rhythm24 have color-coded lights for a quick glance at your heart rate zone.

Most guidelines use five training zones, outlined below:

It is commonly recommended that 80% of runs should be at low or easy intensity (zones one to three) and 20% of runs should be hard or high intensity (zones four and five) (Seiler, 2010). This will allow for good recovery and improved fitness

Regardless of your running goals, a heart rate monitor can help you reach them. Photo: iRunFar/Eszter Horanyi

How do I train for running using my heart rate monitor?

Some runners will monitor heart rate during activity to gauge fitness level and provide objective data to determine run exertion and pace. Tracking heart rate during a particular workout or course over time is a good indicator of fitness gains. Improved cardiovascular fitness will mean that you will be able to run faster at a lower heart rate, and your heart rate will drop faster between intervals or after workouts. A good way to monitor changes in fitness is to continuously monitor heart rate, both at rest and during activity. Wearing a heart rate monitoring watch like the Garmin fēnix7 – Solar Edition makes this easy.

Training within specific heart rate zones based on a percentage of your maximum heart rate is a widely used training method. Varying training runs among the different zones means you will be running at different intensity levels. This variety of easy and hard training helps build aerobic capacity and lactic threshold while emphasizing good recovery. While it is possible to do these workouts based on pace or perceived exertion, using your calculated heart rate zones is another way to ensure your easy days are truly easy and your hard days are hard enough. In an article by Johnson et al. (2017), researchers found similar outcomes between heart rate and perceived exertion training, but training using heart rate improved the accuracy and precision of target zones and was helpful for beginner runners who may not have the experience to accurately determine their rate of perceived exertion for specific workout types yet. For more information and resources about using heart rate in your training, check out some prior iRunFar articles, An Inconvenient Truth: Why Heart Rate Always Matters and Listen To Your Heart: Tips for Navigating Heart-Rate Training.

It is important to note that many factors can influence heart rate. Stress levels, hydration status, heat, humidity, caffeine intake, sleep, age, and certain medications and supplements can all alter heart rate at rest and during a run. Care should be taken to monitor your perceived exertion in addition to heart rate and adjust your workout to avoid overexertion or heart illness (Achten & Jeukendrup, 2003). The maximum heart rate calculation used to determine training zones is simply an estimate and does not take into account any of the above factors.

What is heart rate variability, and why would I track that?

Heart rate variability (HRV) is the measurement of time between individual heartbeats. For those familiar with ECG tracings, this would be the measurement of the R-R interval of each adjacent beat. These are normal, very small variations measured in milliseconds. Heart rate variability is influenced by both your body’s sympathetic nervous system, which is associated with higher stress and fight or flight mode, and the parasympathetic nervous system, which is associated with lower stress states and rest. High stress levels from things like illness, emotional taxation, overtraining, poor recovery, dehydration, and more will result in lower HRV.

Conversely, a more relaxed, less stressed, and well-recovered state will result in higher HRV. The Garmin fēnix7 – Solar Edition is an excellent heart rate monitor to measure your HRV. Tracking your HRV numbers can help guide your training intensity as they indicate your fitness and recovery state (Kiviniemi, 2007). It is important to note that these numbers are very individual, and looking at your personal trends and fluctuations is more beneficial than comparing your HRV numbers to someone else’s (Shaffer & Ginsberg 2017). For more information on HRV, check out What the Heck is Heart Rate Variability? for a very thorough discussion of the ins and outs of HRV and its utility in training.

The Myzone MZ-Switch can be worn either with a chest or forearm strap. Photo: iRunFar/Eszter Horanyi

Can I track heart rate variability with a heart rate monitor?

Heart rate variability requires a heart rate monitor to be calculated. The most accurate calculations will be from ECG chest strap monitors like the Polar H10, though optical heart rate monitors like the Garmin fēnix7 – Solar Edition are improving in their ability to calculate HRV. Many Garmin GPS watches and the Apple Watches can record HRV and will report these in their respective apps and on the watch if you are taking a spot reading of HRV. Several third-party apps can pair with your chest strap HRM and provide an HRV readout that can be trended. It is recommended that these readings be taken while at rest, such as first thing in the morning after waking up so that they will be most accurate.

What are the two types of heart rate monitors?

ECG and optical (PPG) monitors are the two types of heart rate monitors used for sports. As detailed above, the ECG monitors, including the Polar H10, use electrodes on a strap around the chest to detect the heart’s electrical activity, tracking the heartbeats and translating the electrical signals to beats per minute or your heart rate.

Optical monitors like the Polar Verity Sense and the Scosche Rhythm24 are most frequently worn on the wrist or arm and use specialized LED lights to detect changes in blood flow through blood vessels under the skin, translating variations in blood volume in the vessels with each heartbeat into heart rate.

What should I look for when buying a heart rate monitor?

Important things to consider when buying a heart rate monitor are cost, battery life, waterproof capability, and your intended use of the device. You’ll also want to consider what other equipment you will use it with. Most of the best heart rate monitors for running have good accuracy while at rest, so if day-to-day use and resting heart rate, sleep tracking, or heart rate variability readings are most important to you, then a GPS watch that has heart rate tracking capability, like the Garmin fēnix 7 – Solar Edition or Apple Watch Ultra, will be a great choice.

If heart rate accuracy during activities is your priority, ECG chest straps like the Polar H10 or the Garmin HRM-Pro Plus are good choices. These can connect to devices using ANT+ technology and Bluetooth to sync with various devices.

If you prefer comfort over absolute accuracy, arm strap monitors still provide excellent readings and are easier to adjust and wear than chest straps. These use optical sensors and ANT+ or Bluetooth to connect to gym equipment, such as rowers or treadmills. They’ll also connect to your smartphone or GPS watch.

If you want to leave your phone and watch behind, all of the heart rate monitors in this guide have onboard memory and can record an activity right on the monitor to be synced with various apps for analysis later.

iRunFar’s Alli Hartz checks her heart rate during an interval workout. Photo: iRunFar/Eszter Horanyi

What type of heart rate monitor is most accurate?

The chest strap heart rate monitor using ECG technology to track and record heart rate is the gold standard device and most accurate. The Polar H10 was our top chest strap heart rate monitor pick.

How do heart rate monitors connect with running watches or activity-tracking apps?

Heart rate monitors use two types of technology to connect with running watches, apps, and exercise equipment.

ANT+ is a low-power wireless network technology that allows sensors from different manufacturers to communicate and share data. This is often used to connect to multiple types of equipment simultaneously, such as watches, treadmills, and bike trainers.

Bluetooth connects heart rate monitors to smartphone apps for tracking and activity analysis. In the past, it was only possible to connect to one Bluetooth device at a time, but improvements in technology mean that many of the heart rate monitors on the market today have the capability of connecting to multiple Bluetooth channels at the same time. The Garmin HRM-Pro Plus can support up to three Bluetooth connections simultaneously.

The above guide is only informational and does not constitute training or medical advice. If you’re new to running or have any health concerns that can be affected by an increased heart rate, consult your healthcare provider to find a safe approach to training. Seasoned runners can also consult with a credentialed running coach if you have questions about your specific heart rate zones or training plan to determine the safest approach to training for you as a runner.

The Scosche Rhythm24 can be worn on the forearm or the upper arm. Photo: iRunFar/Eszter Horanyi

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