When it comes to choosing the best heart-rate monitor chest strap for your workout, many of the factors in your buying decision will be based on personal preferences and your workout regimen. Here are a few things to look at while shopping.
Strap width: Before you buy, consider whether you'd be more comfortable with a heart-rate tracker that uses a slim strap or a wider one.
Module size: Some chest straps use tiny modules (the plastic puck-like part) that don't extend over the edges of the strap. Others, however, use larger monitors to measure your heart rate. Which style you choose to track your workout depends on your comfort preference.
Internal storage: If you don't like to hold your smartphone during your workout, opt for a heart-rate training monitor that can store your data in its own built-in storage. You can later transfer your heart-rate reading to your phone via your monitor's companion app.
Metrics: Consider what you want to monitor during your workout. Higher-end models capture real-time data covering everything from run cadence to stride length, as well as things like blood pressure, calorie burn and heart-rate variability to help you reach your fitness goals, while more basic models might track only your heart rate.
Battery: A wearable chest strap monitor can have all kinds of power sources. Some have a rechargeable battery. Others may have super-long battery life, but the battery isn't user replaceable or rechargeable. A longer battery life is always convenient -- no one wants a monitor to peter out during a run -- but there are lots of options. Make sure to check the description for battery life before buying a monitor.
Chest strap vs. wrist-worn heart-rate monitors: Chest strap and wrist-worn heart-rate monitors are both used to measure heart rate, but they use different methods to provide readings.
Electrical heart-rate sensors, found most commonly in chest strap heart-rate monitors, can detect electrical currents produced by your heart, somewhat similarly to what is done at the doctor's office with an ECG. These are considered the most accurate heart-rate readings because the electrical sensor can handle measuring your heart rate even during vigorous activity.
Optical heart-rate sensors use an LED light to track your pulse rate in the arteries as blood pumps through them. Optical heart-rate sensors are found in smartwatches and are useful to read your heart rate while at rest or walking, but are less reliable for high-intensity activity because the readings can be distorted.
ANT Plus vs. Bluetooth: Most wrist-worn heart-rate monitors like the Apple Watch use Bluetooth, which only lets you connect to one device. For example, if you're recording an outdoor run, you can only connect your Apple Watch to your iPhone.
ANT Plus technology, however, lets you wirelessly connect to multiple devices at once. This is a good option for athletes who are trying to track data from multiple sources. You can find this form of technology on devices like chest strap heart-rate monitors, indoor or outdoor bike computers and some smartwatches.
However, if you're planning on using a device that uses only ANT Plus technology and want to connect it to your smartphone, know that some Androids have ANT Plus technology capabilities, while iPhones do not. To find out if your device is capable of connecting to your Android, you have to find the ANT Plus Plugins app in the Google Play store and browse its compatible device directory. If you have an iPhone or an Android that does not have the capability to connect to your ANT Plus device, you will need an adapter to add to your phone.
Most people prefer the Bluetooth option because it connects faster and it's easily found on most devices. The good news is there are many heart-rate monitors that include both ANT Plus and Bluetooth to make the user experience easier.
When used correctly, the best heart rate monitors can help you unlock a new level of athletic performance, no matter whether you're cycling, running, or performing any other endurance sport.
Their most basic requirement is to provide consistently accurate heart rate data - measured in beats per minute (BPM). They then need to connect to a smartphone, computer or other device to transmit this data to be recorded.
But as is often the case, and as I've found in over two years of testing heart rate monitors, not all are created equal, even when they do manage those basic needs. For example, the Garmin HRM Pro Plus is by far the most feature-rich in this list, with accelerometers that measure advanced running metrics, but it will come at a premium. For a more affordable choice that does the basics well, the Polar H9 is the one I'd buy and I think most people would be happy with how it performs. Of course, you may have specific requirements for your circumstances, so read on for help choosing the best heart rate monitor for you.
The other reviewers and I here at Cyclingnews all prefer the original chest strap design, as it's still the best for accuracy, but optical sensors built into forearm straps or smartwatches are also popular for their comfort, so we've not excluded those entirely.
For the past two years, I've been using all of the heart rate monitors below and more - often two or three at a time - to work out which is best. I looked for easy connectivity, consistent and accurate measurement, good battery life and a comfortable secure fit. I also tested out each product's extra features like onboard memory and accelerometers, and have compiled my pick of the best heart rate monitors below.
Best heart rate monitors: Quick list
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Best heart rate monitor for cycling
(Image credit: Josh Croxton)
A great heart rate monitor that's comfortable, secure and consistently accurate
Connectivity:
Bluetooth and ANT+
Battery:
CR2025 (400 hours)
Waterproof:
30m depth
Concurrent Bluetooth connections:
2
Added features:
Onboard memory, HRV
How easy to adjust?:
9/10
View at AmazonView at REI.comView at Amazon+
Third electrode and silicone gripper
+
Can measure HRV
+
Quick and easy one-handed adjustment
+
Available in two sizes
-
Lacks advanced features
Polar claims the H10 is the most accurate on the market - accurate to +/- one millisecond - thanks to a third electrode and silicone grippers to keep it in place. In over two years of testing, I haven't had a single issue, so cannot refute those claims. With that said, given most other chest straps here have performed similarly well, I wouldn't buy the H10 for that reason alone.
The reason I would buy it is the super-simple adjustment and extremely comfortable, secure fit. The added bonus of silicone grippers is that you can run it looser than usual without it slipping, and while I don't personally suffer much from chest strap discomfort, I know it's an issue that plagues a few. Swapping to an optical sensor such as a smartwatch is one option, but the downside to that is a reduction in the accuracy of your data, which is common with optical sensors.
Comfort aside, the H10 is entirely waterproof, can be worn while swimming and can also record your heart rate variability — though you'll need to use it in combination with one of the brand's smartwatches to take advantage. It can connect to two concurrent devices with Bluetooth, and it uses a CR2025 (2.5mm thick) battery, rather than the more common 3.2mm thick CR2032.
Best budget heart rate monitor
(Image credit: Josh Croxton)
Best budget heart rate monitor
Connectivity:
Bluetooth and ANT+
Battery:
CR2032 (500 hours)
Waterproof:
IPX7
Concurrent Bluetooth connections:
3
Added features:
None
How easy to adjust?:
6/10
View at WahooView at Backcountry.comView at Amazon+
Status LEDs allow easy check of battery and power status
+
Waterproof enough for a downpour
+
Easy-access (but secure) battery
-
No advanced features at all
-
Slightly complex adjustment
-
Occasional data drops
By far the cheapest on this list, the Wahoo Tickr is the best budget heart rate monitor for anyone who wants a no-frills chest strap without all the bells and whistles with both Bluetooth and ANT+ and a strong warranty in the case of issues.
The strap connects via the two snap-on buttons at the pod. This means they come in close contact with your (often sweaty) skin, which can accelerate corrosion if you don't keep on top of washing it. It also means the Tickr gets switched off when you remove it, which helps battery life. Despite this, although Wahoo claims around 500 hours of use before the CR2032 coin cell battery needs replacing, I've found it usually lasts around half that (which is still plenty, and forgivable at this price). The battery cover is secure - it's dust and waterproof rated to IPX7 - and is easily removed with a coin, meaning battery changes take just seconds.
Adjustment of the strap is a fairly straightforward affair, too, but it does require both hands and is easier to do when removed. It holds pretty well though, so should be a one-time job.
For ease of use, the Tickr range can simultaneously connect to three devices, which is particularly useful for indoor cycling, as it enables you to control your headwind fan whilst riding on Zwift via your laptop, or track your heart rate via a cycling computer and a phone at the same time. In our testing, data has been consistent and accurate, tracking within a single BPM against the more expensive Tickr X on both average and maximum heart rates.
I've experienced a handful of data drops during testing, which is clearly something to bear in mind, but a few seconds of lost data isn't something I'm ever worried about in a normal training session. If you are, however, Wahoo support has never let me down in the past, so I'd still be happy to recommend the Tickr to anyone with a keen eye on budget.
Best value heart rate monitor
(Image credit: Josh Croxton)
Best value heart rate monitor - a basic all-rounder that just edges the Tickr on performance
Connectivity:
Bluetooth and ANT+
Battery:
CR2025 (400 hours)
Waterproof:
30m depth
Concurrent Bluetooth connections:
2
Added features:
None
How easy to adjust?:
9/10
View at Amazon+
Easy to adjust one-handed
+
Super comfortable and secure
-
Lacks advanced features
-
Higher price than the similarly-functioning Tickr X
The Polar H9 doesn't come with any added bells or whistles like onboard memory or accelerometers. It's not the cheapest here (the Wahoo Tickr wins that crown), and Garmin's HRM Dual offers a better battery life. However, when you combine everything into a single device, the Polar H9 is my favourite heart rate monitor for 'basic function', ie monitoring my heart rate while cycling or running, and the reasons are as follows:
Firstly, in my testing, it has provided more accurate and consistent data than the cheaper Wahoo Tickr, which makes it worth the slightly higher price in my opinion. Secondly, while the Garmin HRM Dual is equally accurate, it is a little more expensive again. Thirdly, it's a darn sight easier to adjust the strap on the H9 than on the HRM Dual, and finally, when it comes time to change the battery, the H9 can be done in seconds (just prize away the flap with a flathead screwdriver or similarly-shaped utensil) while the HRM Dual requires a tiny screwdriver to remove four small screws.
To cap it off, it's comfortable and stays secure, so unless you're specifically chasing a truly budget price, a huge battery, or need the added features, this is the best heart rate monitor for you.
Best heart rate monitor for battery life
(Image credit: Josh Croxton)
The best heart rate monitor for battery life and budget HRV support
Average Amazon review:Connectivity:
Bluetooth and ANT+
Battery:
CR2032 (1277 hours)
Waterproof:
1 ATM
Concurrent Bluetooth connections:
2
Added features:
HRV support
How easy to adjust?:
3/10
View at AmazonView at WalmartView at REI.com+
3.5-year battery life
+
Supports heart rate variability
-
Complex and difficult to adjust
-
Difficult to replace the battery
The HRM Dual is Garmin's answer to budget heart rate tracking, but its retail price is still more expensive than both Wahoo's Tickr and Polar's H9.
With that said, it can often be found discounted, which increases its appeal. Where it stands out is with its claimed 3.5-year battery life (assuming an hour per day on average) and the ability to monitor heart rate variability (when paired with an appropriate app).
Beyond that, the HRM Dual is a reasonably basic heart rate monitor, so it doesn't come with the bells and whistles of onboard memory and swim/run dynamics. Its construction also leaves a little to be desired, as the three-part adjustment system is unnecessarily complex to use. This is frustrating because Garmin clearly knows how to do it well, as the more expensive HRM Pro is by far the easiest to adjust on this list.
Furthermore, it's a good job the battery life is so good because when it comes to replacing the CR2032 inside, there are four tiny screws which are fiddly and easy to damage. And that assumes you have a screwdriver small enough in the first place since it doesn't come with one.
Unless you're specifically after huge battery life, then in my opinion, the Polar H9 is a better choice at their respective recommended retail prices. I'd buy it at a discount though, and given that's a common occurrence, I've included it in the list.
Best heart rate monitor for Zwift
(Image credit: Josh Croxton)
The best heart rate monitor for Zwift
Connectivity::
Bluetooth and ANT+
Battery type:
CR2032 (160 hours)
Waterproof:
IPX7
Concurrent Bluetooth connections:
1
Added features:
ANT+ to Bluetooth bridge, internal memory
How easy to adjust:
6/10
View at Amazon+
Can act as ANT+ to Bluetooth bridge
+
65-hour onboard memory
+
Double-tap controls
-
Slightly complex adjustment
The 4iiii Viiiiva is my pick as the best heart rate monitor for Zwift for a couple of reasons. The first of those is its ability to act as an ANT+ to Bluetooth bridge. Most smart trainers, power meters and heart rate monitors these days can work with Bluetooth, but too many connections can cause dropouts, and some devices such as Apple TVs and cheaper laptops have a limit on the number they can work with at one time. Running the smart trainer and power meter via ANT+ to your heart rate monitor, and then transmitting all three data streams via Bluetooth to your laptop frees up valuable Bluetooth channels so you can listen to music through your headphones, or use your wireless keyboard to talk to your fellow Zwifters!
The second reason is that it also stores up to 65 hours of your ride data, so that if your file corrupts, you can recover it. Nobody likes to lose their data, but if you race on Zwift in races where dual recording is required, it could save you bragging rights or even prize money.
Beyond those two key USPs, the Viiiiva is a decent all-rounder too. I've not had it long enough to get through 160 hours of riding, but reassuringly I'm still on the first battery. I've not seen a single power dropout yet, both when connected to an Apple Watch, an iPhone, a bike computer, TrainerRoad and Zwift.
Best heart rate monitor for running
(Image credit: Josh Croxton)
The best heart rate monitor for advanced running metrics
Connectivity:
Bluetooth and ANT+
Battery:
CR2032 (365 hours)
Waterproof:
5 ATM
Concurrent Bluetooth connections:
2
Added features:
Run & swim metrics, onboard memory, HRV
How easy to adjust?:
10/10
View at AmazonView at WalmartView at Jenson USA+
Super easy to adjust one-handed
+
Swim metrics & running dynamics
+
Onboard memory
-
The highest-priced chest strap heart rate monitor around
The HRM Pro Plus is the best heart rate monitor in Garmin's range, with both ANT+ and (unlike the brand's HRM-Run or Swim) Bluetooth compatibility.
It's the highest-priced chest strap on this list, but it does come with a long list of added features. Whether you actually need them is a question you'll need to ask yourself.
It features onboard memory, and will automatically measure your heart rate data and then push it to your device when you next connect it to Garmin Connect. For cyclists, it'll easily pair with your Zwift-running device or any brand of cycling computer. And for dedicated runners, it can also track detailed running metrics such as ground contact time, stride length and more. These are seriously impressive metrics, but you do need one of Garmin's smartwatches to take advantage of some, you can't access them all via a smartphone.
The strap is by far the easiest on this list to adjust; it's a one-handed affair and it doesn't self-loosen over time, it also stays put without being worn too tightly.
Like many others here, the battery is a CR2032 coin cell and Garmin claims it will last around 12 months, with an hour's use per day, which equates to 365 hours of training time between changes. My personal testing saw a lifespan of around half this, but integrating the heart rate monitor into my daily training regime alongside all the others in this list is more anecdote than science.
Thankfully, the battery change on the HRM Pro Plus is a much more straightforward affair than it was on the older HRM Pro.
The pod itself cannot be removed from the strap, which means washing needs to be done by hand, rather than through the washing machine, and Garmin suggests you do that after seven workouts or after every pool swim. For those planning on swimming a lot, the HRM-Swim does come with a wider strap, which helps it stay put better, especially useful for those not wearing a wetsuit, swimsuit or triathlon vest over the top.
Best heart rate monitor for 24-hour tracking
The Whoop 4.0 comes with a proprietary portable wireless charger that can be clipped into place, charging the Whoop itself while you wear it
(Image credit: Josh Croxton)
Best heart rate monitor for tracking recovery
Connectivity:
Bluetooth
Battery type:
Rechargeable
Battery life:
Approx 3-4 days
Concurrent Bluetooth connections:
2
Added features:
Connected Whoop app
How easy to adjust?:
8/10
Whoop 4.0
$30
/mth
Visit Siteat WHOOP+
Recharge without removing
+
Lightweight and unobtrusive
-
Not as accurate as a chest strap
-
Expensive by comparison
Buying a Whoop 4.0 requires a monthly subscription that not only gives you the wrist strap itself but access to Whoop's extensive heart rate, respiratory rate, blood oxygen and skin-temperature monitoring app. Whoop's premise is built primarily on heart rate variability (HRV), which is basically the variation in time between each of your heart's beats, measured in milliseconds.
The theory is that a higher HRV (when compared to your individual average) means you are fresher, or more recovered. Wear the Whoop 24/7 and it will collect this data alongside your activities to monitor your strain vs recovery (incl. sleep) and provide guidance on how to improve. It's a seriously deep data dive that most people won't need, but for committed athletes looking to optimise their life around training, it could be the tool to unlock the next level of performance.
It's clever in that the charger is a portable slide-on battery pack that you wear, and the device itself is waterproof enough to be worn in the pool, the shower, or the sea so you'll never lose a moment's data. However, bear in mind charging is necessary every three to four days. Using the app, you can even relay the heart rate to third-party devices such as cycling computers, should you want to avoid using a chest strap at the same time, and when your Whoop detects an activity, it will not only automatically figure out if it was a ride, a run, mountain biking or more (which it's really good at) and it can then be synced to Strava, Training Peaks or Apple Health.
You need to ensure it's tight against the skin for consistent results, but in my testing, I've found it to be accurate enough for its purpose of tracking overall fatigue and freshness, even if the beat-by-beat measurement might be less perfect than chest straps during exercise.
Best heart rate monitor watch
(Image credit: Josh Croxton)
Best heart rate monitor watch
Connectivity:
Bluetooth, ANT+, WiFi, dependent on model
Battery type:
Rechargeable
Battery life:
14 days +
Concurrent Bluetooth connections:
Dependent on model
Added features:
Tells the time - and a lot more!
How easy to adjust?:
10/10
+
Functional well beyond a heart rate strap
+
The amoled screen is clear and bright
+
Easy to use and configure
-
Really expensive price if all you need is heart rate data
-
Not as accurate as a chest strap
When I originally wrote this guide, I threw in 'whichever smartwatch you already own' as a bit of a leftfield option, basically because most of them monitor your heart rate without having to buy a dedicated strap. Today I've upgraded that option to specifically call out the Garmin Epix series, because it offers every function you need from an everyday smartwatch, such as the time, alarms, notifications, contactless pay, and on-device Spotify music, alongside GPS tracking and workout metrics such as Vo2 Max, pace, stride length and so on. You can even pair it with the HRM Pro Plus above for super thorough running metrics, but its an expensive pairing that only the most committed athletes will benefit from.
Ironically, I actually personally prefer the Apple Watch Ultra over the Garmin Epix ecosystem, and if like me you're not all that interested in checking your vertical oscillation when running, and (importantly) you own an iPhone, then the Apple range might be your pick too. However, the battery life on the Epix is... well... epic, at around two weeks between charge, while the Apple devices are a couple of days at most. The Garmin also works equally well no matter your choice of phone, while the Apple Watches are, naturally, slightly more integrated with iPhones.
Regardless of your choice, the main thing they both offer is the ability and convenience to wear them 24-7. They'll give you a heads up if your heart rate starts beating an irregular rhythm, and they'll be ready to hand - almost literally - whenever you start your ride, run, swim or Extreme-Ironing session.
How to choose a heart rate monitor
Let's start with the basics: In the context of sport, it is a wearable device that can read your heart rate data. It will then transmit the data to a device, like a smartphone or a bike computer, that lets you see it in real time and record it for later analysis.
Unfortunately, as is often the way, there isn't one best heart rate monitor for everyone; each has its pros and cons. Choosing a heart rate monitor is a decision you'll need to make based on your needs, so the first step, naturally, will be understanding what those needs are.
Do you prioritise accurate heart rate data during exercise over the convenience of wearing something all day like a smartwatch? If so, then a chest strap is going to be the best heart rate monitor for you.
Are you a multisport athlete who wants to be able to track your running or swimming metrics in addition to your heart rate? If so, then one of the more high-spec heart rate monitors will be needed, such as the Tickr X (for running) or the Garmin HRM Pro (for running and swimming).
Alternatively, if your reasons for tracking heart rate are not directly related to exercise, but more that you want to track it in everyday life, a wearable such as a smartwatch or a fitness tracker like the Whoop would likely be a better heart rate monitor for you.
Those are some of the basics, but no doubt as you've worked through my list of recommendations above, you'll have had some questions about some of the jargon and terminology I've used. Below, I've rounded up some of the more common questions in order to help you make your decision.
Electrical impulses or beams of light? Which one is best for you?
Since their inception in the 1970s, heart rate monitors have relied on measuring the electrical impulses created by the muscles in your heart as it beats.
It’s similar to what happens when you get an echocardiogram (ECG) at the hospital, only with two or three sensors instead of the twelve commonly used for medical examinations. The electrical sensors measure a small electrical output, and the control unit relays this information to your device of choice (or stores the information for later analysis).
Recently, optical sensors have become more common, especially in multi-sport offerings. These work by shining a light into your skin and measuring the variance in blood flow. While both systems rely on physical contact to gather their readings, optical sensors tend to be used in arm- or wrist-based systems where the variance can be seen.
One problem with this is that a smartwatch is rarely worn as tightly as an elasticated chest strap and as such optical systems tend to be more prone to issues over rough terrain or when running, as bumps can briefly break the all-important contact between skin and sensor.
In simple terms, the best thing for measuring your heart rate will almost always be a chest strap, but if you’re curious about general trends and day-to-day heart health too, a wrist-based optical system will likely be more up your street for its comfort, convenience, and the onboard computer that will process the data rather than relying on being paired to a phone or bike computer.
If you want to run a hybrid system, smartwatches will often have the ability to monitor your heart rate independently using the optical sensor on the back, as well as pair with a dedicated HRM strap for more accurate in-sport measurements.
If you’re still in two minds we have a dedicated guide to wrist vs chest straps, as well as a separate guide to the best smartwatches if those are what you want.
Heart rate is often a rider's first introduction to structured training - perhaps beyond 'perceived effort' or a hill and a stopwatch - and it should always remain a key part of the picture, no matter the amount, intensity or type of training an athlete is undertaking.
Within the context of cycling performance, the best heart rate monitors are regularly overshadowed by the best power meters. These are better for monitoring your training since they offer a more immediate and consistent measure of physical output. However, even with a power meter, heart rate should never be ignored.
Heart rate can also help to identify fatigue to prevent overtraining, especially with the help of heart rate variability (HRV). Want to know how? Check out 'what is HRV?'
We, cyclists, can sometimes have an insatiable thirst for data. Speed, power, cadence, and even blood glucose (see our Supersapiens review if you've missed this phenomenon) can be monitored alongside heart rate. All of these sensors will ultimately need to be connected to something that can translate the raw data into something more visually palatable, which is usually your smartphone or a cycling computer. Most fitness equipment can connect using ANT+, which is a Garmin-created protocol. However, rarely will a smartphone, tablet or laptop use anything other than Bluetooth.
We've got a full explainer of what ANT+ is but we'd suggest you use a Bluetooth device since this will prevent you from needing to buy an ANT+ adaptor for your smartphone.
Fortunately, most heart rate monitors will have the capability to do both ANT+ and Bluetooth transmissions simultaneously, allowing you to hook up wirelessly to your cycling computer of choice and non-ANT+ devices like your laptop or tablet at the same time without a dedicated adaptor.
Beware, some of Garmin's devices (the HRM-Run & HRM-Swim) are still ANT+ only.
IPX7, IP67, 5ATM? Can someone please make sense of this?
Waterproof ratings are a complex mix of numbers and letters that need a bit of decoding before you can understand their meaning. Luckily, it's pretty easy to do.
IP ratings stand for Ingress Protection, and the two subsequent digits represent protection against solids and liquids respectively. The first digit, representing protection against solids like dust and dirt is a rating between 0 and 6. The larger the number, the better the protection, while an X means it hasn't been tested. The second digit, representing protection against liquid ingress - ie water - is a rating between 0 and 8, and again, the bigger the number the better.
ATM ratings focus solely on waterproof pressure rating. They are most easily defined by multiplying the number by 10, to get the depth at which your device can handle pressure. For example, a device with a 5ATM rating can sustain pressures equivalent to what you'd find in water at a depth of 50 metres.
If you run or swim then a heart rate monitor can do more for you than just measure your heart rate, it can monitor your stride length, vertical oscillation, cadence, and even your swimming pace and form.
Of course, whether you actually need these features is a question to ask yourself, since smartwatches can often do the same, smartphones can often handle the running metrics, and some running shoes offer these added features. It all comes down to what you need and what you already have.
When considering chest strap heart rate monitors, if you are particularly sweaty then make sure you get something that is easily washed. The control unit of most chest straps pops off, and keeping it clean will save you from salt corrosion. Most devices recommend being hand washed after each use, and then a trip through the washing machine after around seven uses. However, since the control unit on Garmin's HRM-Pro is fixed, this needs hand washing each time. Of course, it goes without saying that different rules apply to smartwatches.
For the basic funciton of tracking your heart rate, this common question is easily answered with 'any of them,' since they are all technically Zwift compatible. However, beyond connectivity, there are some considerations that make some better than others for Zwift and the world of indoor cycling in general.
As touched on above, chest-based heart rate monitors are usually more accurate than optical wrist-based monitors, so if you're after accuracy, make sure any heart rate monitor you use in Zwift is chest-based.
Next, riding on any of the best smart trainers is always a sweaty affair, even if you set yourself up in a freezer, and as such corrosion resistance is a more pertinent issue than for riding outdoors.
Furthermore, Zwift and other indoor cycling apps can require a multitude of sensors transmitting simultaneously. While all are compatible, if you're running a particularly complex data setup then make sure you opt for something with both Bluetooth and ANT+ to help avoid unwanted interference issues.
Our pick as the best heart rate monitor for Zwift is the 4iiii, because alongside being secure, comfortable and accurate (in my testing), it can also act as a Bluetooth bridge for your power meter or your smart trainer. This means instead of connecting multiple devices to your laptop, potentially reaching your limit or causing interference, you can send all the data in one stream, reducing the chance for dropouts.
Sure, the size and weight of something you're going to need to carry on your wrist or your chest is important. You obviously don't want a 3kg house brick strapped to your chest whilst you're trying to run or ride. However, the reason we've not mentioned it in our guide or product recommendations above is that the differences are so small that it's not worth comparing.
A heart rate strap that weighs 19g vs another at 21g won't be noticeable, nor will one that's 8mm thick compared to another at 10mm. Metrics that make more sense to compare are things like battery life, ease of adjustability and how securely and comfortably they stay in place when worn.
HRV stands for Heart Rate Variability, but what does it mean? It's a common misconception that your heart beats at a perfectly regular pace, and by that, I mean if your heart is beating at 60bpm, it isn't beating exactly once per second. According to Stephanie Shell, a Senior Physiologist specialising in recovery at the Australian Institute of Sport, the time between each beat might differ by between around 20 and 200 milliseconds.
HRV, or Heart Rate Variability, is the measurement of the irregularity in these intervals. We have a detailed deep dive explaining what is HRV, but the basic overview is that this is directly tied to our body's autonomic nervous system, and that a larger HRV number (compared to our own baseline) is a good indication of being well-recovered and ready to take on more training stress.
In each of the product recommendations above, I've rated how easily the heart rate strap can be adjusted. Many will only need adjusting every few weeks as they loosen or go through the wash, but if a heart rate monitor is complex to adjust, it can often lead to it being too tight or too loose. You can bet that the one time you find it's slightly too loose is when you're already midway through a ride, and you don't want to have to strip your layers off to be able to adjust it to prevent it from slipping down and becoming a belt.
As part of my testing, I spent time fitting and adjusting each of the straps in turn, making notes to compare how easily it could be done, whether it could be done one-handed, or whether it baffled me more than trying to free a pair of tangled headphones.
How do we test the best heart rate monitors?
My testing for this guide to the best heart rate monitors has been an ongoing process for almost two years. Each test starts with an unboxing, during which I make a note of the packaging for its eco-friendliness. All brands use some form of plastic in their packaging, but I usually find Wahoo is the best in this regard.
For chest straps, I then read the care instructions and make a note of washing recommendations, before removing the battery cover in a trial run battery swap, noting the difficulty. Next up comes the adjustment, and working out how easy - or difficult - it is to fit the strap. On the chest straps, Garmin's HRM Pro Plus wins this, with close seconds coming to both Polar options.
Next, I research the claimed features and qualities of each heart rate monitor and try out these features during testing to confirm they do what they should, and to experience how said feature might benefit a user's workout.
In the absence of having a doctor with an ECG machine on hand for all of my workouts, I improvised a way to confirm accurate readings. Throughout testing, I spend a time wearing three (sometimes four) heart rate monitors for my workouts - two chest straps and one or two wrist straps, depending on what I'm testing. This compares the readings for each heart rate monitor against at least two others and lets me weed out any devices with inaccurate data or poor connectivity. As is widely accepted, the chest straps performed best here, while optical wrist sensors tended to struggle to keep up with quick changes up or down, especially when running or mountain biking, as this shakes the wrists more than indoor cycling.
I then set them all to the same length before wearing them individually to note comfort and how securely they stay in place. Thankfully all heart rate monitors I've tested have been comfortable enough that they are easily forgotten once in place, but I do find the Polar H10 is most comfortable and secure.