Best Heart Rate Monitors for Running: Chest Straps and Arm Straps Worth Buying

Introduction

Most running watches now carry a built-in optical heart rate sensor, but if you want to sharpen the accuracy of your training and recovery metrics, investing in a dedicated heart rate monitor still pays off. Prices range from around £40 to £140 and beyond, from basic BPM trackers to straps that add running form metrics. We have tried all of the latest chest straps and arm straps for accuracy, comfort, connectivity, and extras, covering Garmin, Polar, Coros, Myzone, Coospo, and 4iiii. Here are the picks that stood out.

Best All-Rounder: Polar H10

The Polar H10 has long been close to the gold standard for chest strap accuracy, and that reputation still holds. If accuracy is all you want, this is the strap to buy: it is exceptionally precise, comfortable for any length of run, and has probably been used in more lab tests than any other strap, with sports science departments frequently handing it out for treadmill and VO2 max testing. The clasp closure is easier to use than hook-and-loop, and the sensor sits softly against the skin rather than feeling rigid.

The feature set is not the most advanced on the market, but the fundamentals are nailed. You get a 400-hour battery life on an easy-to-replace coin cell, two simultaneous Bluetooth connections, and a sensor pod that is easy to detach at the end of a run. At roughly £80 in the UK, just under $90 in the US, it is keenly priced for this level of accuracy, and because it is an older strap Polar has not replaced, it regularly appears discounted during sales periods like Black Friday.

Best Premium Option: Garmin HRM Pro Plus

The Garmin HRM Pro Plus costs a little more, around £120 in the UK or $130 in the US, and adds a genuinely useful set of extras on top of excellent accuracy. It records running dynamics such as ground contact time and vertical oscillation, does running power natively, works as a treadmill speed source, and stores data onboard so it can sync directly to the Garmin Connect app later. It also transmits heart rate from swim sessions to a Garmin watch once you are out of the water, which makes it especially appealing to triathletes.

Comfort is excellent, with a strap that has slightly more give than the Polar, and in testing it has proven durable and dependable for benchmark runs. Battery life is a little shorter than the H10 at around a year of training per coin cell, but you now swap the battery without a screwdriver, a major improvement over the earlier HRM Pro. Connectivity is also stronger with three simultaneous Bluetooth connections, ideal for indoor setups with multiple devices.

Best Budget Chest Strap: Coospo H9Z

The Coospo H9Z proves you do not need to spend triple figures for reliable heart rate data. In testing against the Polar H10 it did not miss a beat, staying accurate throughout, which is more than can be said for several other cheap straps. At around £36 or roughly $45, it is a genuinely reliable monitor at a low price, and it even held up beat for beat against a far more expensive ECG-capable strap.

It uses a rechargeable battery, so you get into a simple charging rhythm, and the audible beep confirms the strap is live and ready to connect, a surprisingly useful touch when you are unsure whether a sensor has detected contact. The strap material is not quite as soft as the premium options, and features are limited to heart rate tracking with no workout storage, but as a dependable, accurate budget chest strap it is hard to argue with.

Best Cheaper Workhorse: Polar H9

The Polar H9 delivers Polar’s well-known accuracy at a lower price, sitting at around £52.50 in the UK or just under $60 in the US. You lose some of the extra features of the H10, but many runners never use those anyway, and the core heart rate tracking remains solid and dependable.

If you were starting fresh with everything now known about heart rate monitors, this is the kind of strap that makes sense as a cheaper H10: the accuracy is there, and that is what most runners actually need from it.

Best for ANT+ Bridging: 4iiii Viva

The 4iiii Viva brings a trick we have not seen elsewhere: it can act as an ANT+ to Bluetooth bridge, letting you connect ANT+ devices to Bluetooth receivers. That matters far more to the cycling community than to runners, particularly for indoor training setups where multiple sensors need to link up, but it is clever, useful engineering regardless.

It also offers 65 hours of onboard workout storage, which is generous, and 160 hours of battery life from a coin cell. At just under £60 in the UK or just under $50 in the US, it is a strong option if you need that bridging capability or extra onboard storage.

Best Arm Strap: Polar Verity Sense

Arm straps have emerged over the last few years as a viable alternative to chest straps, and the Polar Verity Sense is arguably the best all-round package of the group, at just under £87 or just under $100. It can be worn on the forearm or bicep, and it even has a swim mode with a goggle clip attachment. The wide strap is comfortable, does not flip over on the arm, and accuracy tested extremely well against a chest strap, matching it beat for beat with only the occasional millisecond of lag on interval rises and falls.

It also stores 600 hours of workouts, so you can run without a watch and sync later, and it is more comfortable than a chest strap on very long efforts where straps can rub. The main annoyance is the small charging cradle, which is easy to lose, and battery life sits at around 30 hours per charge, less generous than some rivals.

Best Newcomer Arm Strap: Coros HRM

The Coros HRM is Coros’s first heart rate monitor, and it is a very well put-together piece of kit at just under £70 or just under $80. It is designed to be worn on the bicep, where Coros recommends it for maximum accuracy, with a slim sensor that protrudes less and catches on clothing less, plus a wide, soft strap that feels light on the arm. In testing it matched the Verity Sense for reliability, tracking the correct rises and falls with only tiny, momentary lag against a chest strap.

The auto on/off is the standout convenience: put it on and it starts tracking and connects to your watch, take it off and it powers down. Battery life is claimed at 38 hours, ahead of the Verity Sense and the Wahoo Tickr Fit, and in testing a two-hour run consumed only about 4% of the battery. You get three simultaneous Bluetooth connections, though no ANT+ connectivity, which is a minor omission for pure runners.

Budget Arm Strap: Coospo Armband

Coospo also makes a budget arm strap that undercuts the Coros and Polar options by a fair margin. It is rechargeable, comfortable, and easy to put on with a stretchy band, and it has been used extensively in recent testing.

Accuracy is where the price difference shows. It uses fewer LEDs than the Polar and Coros sensors, and testing revealed slightly more frequent off readings and a touch more lag, though it remained mostly accurate and is definitely an upgrade on the optical sensor in a watch. As good value for money, it makes sense if your budget is tight.

Wearable Anywhere: Myzone MZ Switch

The Myzone MZ Switch is the left-field pick, at £140 or $160. It was the first strap to bridge chest strap ECG and optical arm strap sensing in one unit, letting you wear it on your chest or on your arms, which is why it earns a place here. The small sensor sits neatly on the chest strap and in the armband, it is rechargeable, and accuracy tested well, with 140 hours of battery life in chest mode and 35 hours in optical arm mode. The Myzone app also converts your effort into Myzone points, which gamifies training and is popular in gyms with live screens.

The catch is price. In a decent sale you could buy both a Polar H10 and a Coros HRM for the cost of this one strap, covering both wear positions that way. It is a genuinely good product, just priced a little too highly for what most runners will actually use.

Buying Advice

If accuracy is your only priority, a chest strap remains the way to go, and the Polar H10 or Garmin HRM Pro Plus are the two most dependable picks. If you want Polar-level accuracy on a tighter budget, the H9 or the Coospo H9Z both performed reliably in testing. Runners who find chest straps uncomfortable, especially on long ultra-distance efforts or under a race vest, should look at the Coros HRM or Polar Verity Sense instead. Just be cautious with unproven budget straps: we have tested cheaper options with dropouts and inconsistent readings, so a bargain is no bargain if the data is not accurate.

Conclusion

A good heart rate monitor feeds better data into the training and recovery insights you have already paid for on your watch, so it is one of the smartest small upgrades a runner can make. Match the strap to your priorities: maximum accuracy, extra metrics, arm comfort, or a crossover design, and any of the picks above will serve you well.