Best heart rate monitor 2021 to accurately measure heart rate during running and workouts

The best heart rate monitors for runners, cyclists, triathletes and gym jocks

The best heart rate monitors will provide accurate heart rate reading, even during basketball
(Image credit: MyZone)

No matter how advanced optical heart rate sensors are, the best heart rate monitors still provide more accurate readings than smartwatches, even in 2021. As popular as they are, running and triathlon watches can only be so accurate, trying to measure heart rate on your sweaty wrist as you exercise.

For those athletes who take training seriously, heart rate sensors are a must, whether it's the chest strap or the armband variety. In some cases, wearing a heart rate monitor is the only option to track heart rate during workouts: weight training, especially when kettlebells are involved, can't be tracked safely and precisely using wrist wearables.

Even the best running watch won't be able to withstand the repeated impact of a kettlebell when doing snatches. Not to mention, your wrist will be pretty bruised if you wear a watch for kettlebell training.

For many, tracking heart rate on the wrist with a fitness tracker or running watch might seem sufficient. Still, precise readings from wrist-mounted optical heart rate sensors can be compromised by many external factors: the wrist moving too much, sweat, hair on the wrist and so on.

Heart rate monitors, especially the chest strap variety, provide more accurate heart rate readings for two reasons: firstly, they don't need to 'see' your skin like optical sensors, and secondly, the sensor is mounted on an elastic strap that fits the torso better.

Some wearables, such as the best triathlon watches, can measure heart rate underwater but just like during running, you'll get more accurate results wearing a water-resistant heart rate monitor. If you are planning on upgrading your running gear, make sure you check out the best running shoes and best running headphones guide too.

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Best heart rate monitors, in order of preference

The Garmin HRM-Pro is T3's top choice for best heart rate monitorsT3 Best Buy Award badge

(Image credit: Garmin)

1. Garmin HRM-Pro

All the best features a Garmin heart rate monitor has to offer

Sensor type: electrode pad/transmitter
Battery type: CR2032
Battery life: 12 months (considering one hour of usage per day)
Reasons to buy
+Bluetooth & ANT+ connectivity+Advanced Running Dynamics+Offline workout support
Reasons to avoid
-Most updates since the HRM-Run will only benefit runners

The Garmin HRM-Pro combines the best features found in other Garmin heart rate monitors, such as the Garmin HRM-Run and Garmin HRM-Swim, making the HRM-Pro the ultimate choice for – well – pros. With the HRM-Pro, you can track advanced running metrics and swimming metrics when linked to a compatible smartwatch.

The running metrics sensor also enables the HRM-Pro to estimate lactate threshold; more precisely, using the Garmin HRM-Pro and a compatible smartwatch (e.g. Garmin Forerunner 745), the algorithm can determine the optimal pace you can run a 10K/half-marathon without completely exhausting the muscles. Perfect for runners who are not overly experienced in competition and would like to train at the correct pace. More on this here.

The Garmin HRM-Pro can also connect to multiple devices simultaneously via Bluetooth and ANT+: you can feed heart rate data into your smartwatch and your Wattbike, all at the same time. Perfect for those athletes who like to track their performance in a million different apps.

This heart rate strap can also collect offline daily activity without a watch. Even if you aren't wearing a watch, maybe because you are charging it or you are performing an activity that requires you to take the watch off (e.g. kettlebell training), heart rate data will still be captured and fed into the Garmin Connect app continuously, as long as you are wearing the HRM-Pro.

The Polar H10 is a precise and versatile heart rate monitor

(Image credit: Polar)

2. Polar H10 Heart Rate Sensor

Precise and versatile heart rate monitor

Sensor type: electrode pad/transmitter
Battery life: 400 hours
Battery type: CR 2025
Reasons to buy
Reasons to avoid
-Chest strap might be too tight for people with girthier torso, even at the longest setting

If you don't want to buy more than one heart rate monitor to track more than one type of sport, your best bet is on the Polar H10. It is the "most accurate heart rate sensor in Polar’s history", and in fact, the Polar H10 can monitor your ticker very accurately.

The best thing is, the Polar H10 has built-in memory for one exercise, so you can wrap the heart rate monitor around your chest, start the exercise in the Polar Beat app and then leave the phone behind. The strap will sync with the phone once you are back home. More on this here.

Polar H10 can connect to fitness apps, sports and smartwatches, gym equipment using Bluetooth and ANT+ connection. Polar H10 can be connected to Bluetooth and ANT+ devices simultaneously so that you can hook it up with your watch and your turbo trainer as well at the same time.

The Polar H10 is also suitable for swimming, although it's not a dedicated swimming heart rate monitor. For the best results, you want to wear a tri-suit or wetsuit over it, so it is pressed closer to your skin as you swim.

As for comfort, the Polar H10 is equipped with the Polar Pro strap that sports a range of little non-slip dots along the inside of the belt. These help the belt stay in position without making it feel too synthetic.

The Polar H10 heart rate monitor also supports Polar's Orthostatic test that records your heart rate variability and "equips you with knowledge about your recovery as well as tools to optimise your training", as Polar explains. You will need a Polar Vantage V or Vantage M to perform this test, mind. 

The Wahoo Tickr X (Gen 2) is lighter and more accurate than everT3 Approved badge

(Image credit: Wahoo)

3. Wahoo Tickr X (Gen 2 – 2020)

Lighter and more accurate than ever

Sensor type: electrode pad/transmitter
Battery life: over 500 active hours
Battery type: CR 2032
Sweatproof: yes
Water rating: IPX7 (waterproof up to 5 ft)
Reasons to buy
+ANT+ running dynamics (when paired with a running watch)+Lightweight design+Can connect to multiple devices simultaneously+Improved strap design+Built-in memory
Reasons to avoid
-Data screens in the Wahoo App are mainly useful for checking running/cycling metrics

Wahoo went the extra mile in 2020 to update the already popular Wahoo Tickr X heart rate monitor. The second-generation Tickr X has an integrated strap design, making it easier to put the sensor on, and the fit feels more secure. As soon as the monitor is on and picked up the heart rate (you might want to apply some water to the back of the strap for better connection), the LED lights on the top of the device starts flashing, signalling it's ready to connect.

And the Wahoo Tickr X (Gen 2) connects fast: I tested it with my trusty Garmin Fenix 6 Pro, and it never failed to recognise the heart rate monitor within a matter of seconds (after the initial paring). The Tickr X can be paired to multiple devices simultaneously, so if you happen to use a smart trainer and a running watch simultaneously, the Tickr X will feed heart rate stats into both.

Runners will enjoy the new advanced running metrics: when paired with a GPS multi-sport or running watch, the ANT+ Running Dynamics will be broadcast on the Tickr X and recorded on the watch for real-time feedback. Should you decide not to use any other fitness wearables for your workouts, you'll be happy to hear that the Tickr X has built-in memory for up to 50 hours' worth of exercising, which can later be synced with the Wahoo App.

Much like the screen on running watches, the Wahoo App functions as the user interface for the Wahoo Tickr X heart rate monitor: you can see your profile and workout history, as well as checking your stats in real-time as you exercise. The Wahoo App has 43 pre-configured profiles, and you can also switch out data screens with others, although it is worth mentioning that most screens are focused on either cycling or running metrics (obviously). So even if you do a 'gym workout' session, your average speed, distance and elevation gain will be recorded too. This is not a deal-breaker issue, however.

The Wahoo Tickr X is a premium heart rate monitor that provides a heap-load of useful features for runners, cyclists and other types of sportspeople. Maybe not for triathletes – it's only moderately water-resistant, but others prefer to work out on dry land.

The Polar Verity Sense is the best heart rate monitor for HIIT and kettlebell workouts

(Image credit: Polar)

Best heart rate monitor for HIIT and kettlebell workouts

Sensor type: optical heart rate sensor
Battery life: up to 20 hours
Battery type: rechargeable battery
Reasons to buy
+Versatile+Great design+Comfortable+Decent battery life
Reasons to avoid
-Poor app design (Polar Flow)

Verity Sense is a serious heart rate monitor for running, swimming, cycling and workouts, but it's also designed to be comfortable and easy to use. The latest from hardcore Finnish fitness brand Polar, it's one of the best heart rate monitors to date to use an optical sensor rather than the traditional electrical one. 

That's why it doesn’t wrap around your chest but instead goes on your arm, which many people find more convenient. It can also attach to your swimming goggles to read your pulse from your forehead. 

Boasting a host of additional fitness features, the Verity Sense has the potential to be a great alternative for those who find chest straps too clunky and smartwatches too unreliable: it's fantastically versatile, feature-rich, and well-priced heart rate monitoring strap – but you do have to contend with a not-so-user-friendly Polar Flow app.

We recommend using the Polar Beat app instead, which is way more user friendly and feeds data back into the Polar Flow app. You can initiate a workout from the Polar Beat app and monitor heart rate and calories burned in real-time using the phone, which acts as an external screen for the Verity Sense strap.

You can also perform tests using Polar Beat, such as the Polar Fitness Test – a VO2 max assessment, basically. Although confusingly, these tests are found under the 'Upgrades' option. It's a bit odd having to use two apps to track your workouts successfully. We've seen worse, but Polar really should look to sort this out soon.

The Garmin HRM-Run is the most accurate heart rate monitor option for runnersT3 Approved badge

(Image credit: Garmin)

5. Garmin HRM-Run Heart Rate Monitor

The best (cheap) option for runners

Sensor type: electrode pad/transmitter
Battery life: up to one year
Battery type: CR 2032
Reasons to buy
+Advanced running metrics+Supports the Garmin Lactate Threshold Test
Reasons to avoid
-Cannot record workouts directly into Garmin Connect

It seems that the majority of runners wear a Garmin running watch nowadays, so getting the Garmin HRM-Run is probably the best option for them. As the name suggests, the Garmin HRM-Run works best for runners and will provide advanced running metrics and precise heart rate readings on land. It is waterproof as well.

The Garmin HRM-Run measures six different metrics: cadence, vertical oscillation, ground contact time, ground contact time balance, stride length and vertical ratio. If none of these makes much sense to you, you'd probably want to hold off before you get the Garmin HRM-Run.

As you'd expect, the Garmin HRM-Run can make you a more efficient runner, but only if you are keen on learning and adjusting your technique. It won't run better for you but will provide you with an ample amount of data so you can analyse your running form in minute details.

Battery life is up to a year – there is no screen or optical sensors involved after all – and the Garmin HRM-Run supports both Bluetooth and ANT+ connections. The strap supplied with the product is comfortable enough and won't chafe your skin.

Most importantly, the Garmin HRM-Run can be used – with a compatible Garmin watch – to perform a lactate threshold test. From Garmin's website: "Lactate threshold is the point where your muscles start to rapidly fatigue. Your device measures your lactate threshold level using heart rate and pace.

When a runner exceeds their threshold, fatigue starts to increase at an accelerating rate. For experienced runners, the threshold occurs at approximately 90% of max heart rate, corresponding to a pace somewhere between 10K and half-marathon race pace. For the average runner, it occurs well below 90% of their maximum heart rate. Knowing your lactate threshold can help you determine how hard to train or when to push yourself during a race."

The MyZone MZ-Switch will help you stay in the zoneT3 Approved badge

(Image credit: MyZone)

Stay in the zone with this brilliantly accurate heart rate monitor

Sensor type: electrode pad/transmitter
Battery life: up to 6 months
Battery type: rechargeable
Reasons to buy
+Light heart rate zone indicator is a nice touch+Integrated ECG and PPG sensors+Stores up to 30 hours of exercise data+ANT+ and Bluetooth connection
Reasons to avoid
-Myzone app is slightly confusing-Feels kinda' cheap-Expensive compared to some other heart rate monitors

The Myzone MZ-Switch is a super versatile fitness companion that will deliver accurate results during almost any workout. With exceptional battery life, a compact and lightweight design and an easy-to-use, feature-rich companion app, you can’t go far wrong here.

There is an ever so slight issue, though: the price. The MZ-Switch doesn’t look like it’s worth £140, nor is it the kind of device you’ll want to show off with pride due to its cheap-looking design, but it does the job it’s been designed to do very well, ensuring it’s ready for whatever sweat-inducing activity you throw at it.

In case you're unfamiliar, Myzone monitors use a different system to other heart rate monitors, the so-called MEPs system. Essentially, the Myzone MZ-Switch tracks which heart rate zone you're in and gives Myzone Effort Points (MEPs) after each workout.

MEPs are similar to all other gamified fitness reward systems, but at first, it can be a bit confusing to see a workout in the Myzone app composed of nothing but coloured lines. However, once you've got the hang of it, it's straightforward enough to use.

The Polar OH1 is a the Verity Sense's predecessor and works great as an optical heart rate sensor for workouts

(Image credit: Polar)

7. Polar OH1

A great optical heart rate sensor for workouts

Sensor type: optical heart rate sensor
Battery life: 12 hours of training
Battery type: Rechargeable 45 mAh lithium polymer battery
Reasons to buy
+More convenient than a chest HRM+Built-in memory+Can be worn as a headband
Reasons to avoid
-Short battery life

One thing that often doesn't come up in the conversation when talking to CF people and the likes is how unpleasant it is to put on a cold chest strap during the winter months. When you are cold, wrapping a cold, damp strap around your torso is not a sensation many will yearn after.

The Polar OH1 is the perfect solution for this problem. This armband is an ideal compromise between precision and comfort: it will provide more accurate readings than a running watch without being uncomfortable to wear.

How so? Although the Polar OH1 uses the same type of sensor as a running watch, the armband sits on your skin better and picks up signals easily and accurately. Running watches have to put up with the bony wrists of yours, not to mention the constant twisting motion of your hands that jeopardises readings as you exercise.

On the downside, the Polar OH1's optical sensor uses more battery power than its traditional counterparts and will 'only' last for 12 hours between charges. This is 12 hours of exercising, mind, so you still won't need to use the charger more than once every other week, but compared to the 1-year battery life of chest straps, it's still much shorter.

The Polar OH1 has a swimming goggle strap clip so you can thread the clip to the strap of your swimming goggles. The Polar OH1 will stay snug against your temple and give you good heart rate readings, even underwater.

The clever light feedback of the mioPOD makes this the ultimate summer heart rate monitor

(Image credit: Mio Labs)

8. Mio Labs mioPOD

Clever light feedback makes this the ultimate summer heart rate monitor

Sensor type: optical heart rate sensor
Battery life: 24 hour
Swimproof: Yes
Reasons to buy
+Precise optical sensor+Measures running cadence+Haptic alert
Reasons to avoid
-mioApp has some usability issues

The mioPOD heart rate monitor – paired up with the accompanying mioApp – is trying to bridge the gap between a passive heart rate sensor and a running watch. It still is a heart rate sensor, not a chest strap but an arm band, much like the Polar OH1, but with some added perks: it has haptic feedback and also visual feedback on heart rate zones.

The latter feature is called Cardio Pilot and it alerts you if you go from one heart rate zone to the other. The haptic feedback helps you notice these changes, even if you are not staring at the mioPOD as you workout. The mioPOD is mainly a good weather/indoor heart rate monitor: it would be hard to work out what the haptic feedback is about if you are wearing a base layer, a jumper and a jacket over the sensor.

The Valencell optical sensor used in the mioPOD is precise and you can also check your heart rate in real-time using the mioApp. The app is okay to use although not the most intuitive compared to the Fitbit App or Garmin Connect. It does have a workout memory, so does the mioPOD which can store 30 hours-worth of workouts.

The mioApp also has a couple of decent fitness features, like measuring training load  (just like Garmin) and recovery status (much like Polar). In the app, you can also see how many calories you burned and even advanced running metrics like cadence. The mioPOD is also swimproof.

Person putting on a cycling jersey with a heart rate monitor strapped around their chest

(Image credit: Wahoo)

How to choose the best heart rate monitor for you?

Which heart rate monitor is best for you depends on the type of sport you do most often and on convenience factors, too. For example, there is no need to get a waterproof Garmin HRM-Swim when you hardly ever swim in a pool. At the same time, don't pick the Polar OH1 arm band if you don't want to charge/replace the battery in your heart rate monitor more than once a year.

When it comes to heart rate monitors, the cream of the crop at the moment is the Garmin HRM-Pro. It combines the best features of the Garmin HRM-Run and HRM-Swim and can be used both in and out of the water. It can also provide advanced running metrics and can be used without a watch too.

If you are after versatility, the Polar H10 is your best bet. It is very accurate as well as being waterproof and able to track heart rate under water. The Polar H10 has a 400-hour battery life, a single-activity memory and it also just comfortable to wear.

For runners, the best option is still the Garmin HRM-Run. Apart from tracking heart rate precisely, it also provides 6 extra running dynamics for the wearer – if it's paired with the correct device/app.

If you are after comfort, the Polar OH1 or the mioPOD arm bands are your best bet. They use optical sensors to track heart rate and have a much shorter battery life than their chest-strap counterparts; they can be worn on the upper/lower arm, making them less awkward to put on and remove.

If you are after ultimate precision, instead of just using good-old tap water, you can apply contact gel on the back of non-optical heart rate monitors, although it is a little bit of an overkill for most athletes apart from pros who need to track every minute change in their heart rate during workout sessions.

What's a good resting heart rate?

Resting heart rate – or pulse rate – is number of times your heart beats per minute (bpm) when you aren't active. This can vary widely from person to person and anything between 60-100 bpm can be considered 'normal' levels of resting heart rate, according to the British Heart Foundation. Pulse rate varies throughout the day and tend to be the lowest at certain stages of sleep.

Athletes, especially endurance athletes, generally have a lower resting heart rate: young, healthy athletes can have a resting heart rate close to 40 bpm or even lower sometimes.  The emphasis is on 'young' and 'healthy' as overworking your body, especially after a certain age, can have a detrimental effect on cardiovascular health. 

Matt Kollat
Matt Kollat

Matt is a fitness fanatic (a.k.a. fitness and nutrition writer) who's been rambling on about all things health and fitness for over two years now here at T3. His achievements include a short-lived fitness podcast called Fit Mentality Podcast and being a judge on the Fit&Well Awards 2021. In his free time, he works out at home, runs, cycles and loves a good ol' walk around the city. He writes about general fitness stuff, fitness tech, workouts, workout gear/equipment, nutrition and much, much more.