Best External Heart Rate Monitors for iPhone and Apple Watch 2021

Scosche Rhythm+ Heart Rate Monitor Supply: iMore

Exterior Coronary heart Fee Screens

Whereas the guts fee monitor on the Apple Watch is sweet sufficient for fundamental exercises, it might not be sufficient for marathon coaching or extra intense exercises. That is as a result of the Apple Watch solely has a lot battery life, and intense exercises can drain the battery sooner than you’d assume because of the fixed coronary heart fee monitoring. That is why we expect you need to get Scosche’s Rhythm+ Monitor Armband for these hardcore exercises and intense coaching periods as a result of it is the perfect exterior coronary heart fee monitor for Apple Watch.

Greatest for Most: Scosche Rhythm+ Monitor Armband

Scosche Rhythm Plus 2 ColorsSupply: Scosche

Now we have examined the Scosche Rhythm+ Monitor Armband and may safely contemplate it the perfect exterior coronary heart fee monitor for Apple Watch. The water resistant (IP68) gadget connects to an adjustable neoprene strap, and it dustproof and waterproof (it may be submerged 1.5 meters for 30 minutes) for even the hardest exercises. Whilst you can put on it anyplace in your arm, Scosche recommends the forearm. (I did my preliminary assessments with it in that location, as properly.) The primary era Rtythm+ had a robust Eight-hour battery life, however the brand new Rhythm+ model can do round 24 hours of exercise time earlier than it wants a recharge, which is much more spectacular.

Each the darkish grey tracker and strap are slim and classy, given that you will seemingly be sporting them in a visual location in your arm. You possibly can slip a shirt on over the Rhythm+ if you wish to disguise it, nevertheless it’s a pleasant sufficient wanting tracker to depart it seen. It does look somewhat goofy when each the Apple Watch and tracker are on the identical arm, however till we have now magical nanobot implants, such is our related gadget way of life.

In apply, it is considerably extra snug than sporting a chest strap throughout heavy-duty exercises whereas being about as correct. The Rhythm+ makes use of each inexperienced and yellow oximeter sensors (described as “PerformTek biometric sensor know-how”) to get a extra exact take a look at your coronary heart fee and blood movement than simply the Apple Watch’s inexperienced sensors alone. Having extra sensors additionally signifies that it updates way more steadily than the Apple Watch.

I wore the Rhythm+ for every week to my common skating practices and weight coaching periods. It proved considerably extra correct from these exercises than my traditional Apple Watch monitoring (I used Bluetooth Sensible to hook up with the Rhythm, nevertheless it additionally provides ANT+ assist for cyclists). My solely concern with the Rhythm+ was occasional tightness when doing arm-related workouts. Though the neoprene strap flexes barely, it isn’t designed to take care of main forearm or bicep flexion.

In contrast to many different chest strap choices, Scosche does not supply a devoted app for viewing your recorded coronary heart fee knowledge. As an alternative, you’ll be able to take a look at it in Apple’s Exercise or Well being apps or obtain a third-party choice like Cardiogram. If you wish to avoid wasting dough, the primary era Rhythm+ can be nonetheless out there for barely much less — simply be warned that it’ll solely have Eight-hour battery life versus the 24 hours of the newest model. The brand new Rhythm+ additionally makes use of the identical charging cradle because the Rhythm24, which we point out beneath.


  • Light-weight
  • Breathable band
  • Frequent heart-rate readings
  • Water resistant


  • Tight match when lifting weights

Greatest for Most

Scosche Rhythm Plus 2 Blue Render

Scosche Rhythm+ Coronary heart Fee Monitor Armband

An armband that screens with out concern of battery drain.

If you happen to’re trying to get higher coronary heart monitoring with out going full in on the chest strap, get this forearm-monitoring as an alternative.

Greatest for Apple Watch: Twelve South ActionSleeve

TwelveSouth ActionSleeveSupply: TwelveSouth

It is a band that you simply pop the case of your Apple Watch into and strap it to your higher arm. This retains the Watch’s sensor securely to your pores and skin, so that you get a extra constant studying, particularly for those who’re bending your wrist loads when you train.

Your Apple Watch, sans band, matches right into a mount with the bottom uncovered, so the Watch’s sensors are unobstructed. The mount has a raised silicone border to guard the Watch from scratches (and preserve it in place).

If you happen to’re proud of the efficiency of your Apple Watch’s coronary heart fee sensor however don’t desire it wrapped round your wrist when you work out, get the ActionSleeve. It is the proper different to the perfect exterior coronary heart fee monitor for Apple Watch.


  • Works with Apple Watch
  • Extra correct readings because of positioning
  • Reasonably priced


  • Uncomfortable for bicep exercises

Greatest for Apple Watch


Twelve South ActionSleeve for Apple Watch

Helps you to use your Apple Watch.

If you wish to keep on with the Apple Watch’s coronary heart fee monitor however need somewhat extra accuracy, the ActionSleeve is ideal.

Greatest for Accuracy: Polar H10 Coronary heart Fee Monitor

Polar H10 Heart Rate MonitorSupply: Polar

The H10 connects to your iPhone or Apple Watch utilizing Bluetooth LE, although you may wish to use considered one of Polar’s apps to get Polar’s particular readings — I used Polar Beat. It is not my favourite app (and requires an in-app buy if you wish to see your coronary heart fee/fats burn breakdown), nevertheless it does the trick. Your coronary heart monitoring may also log in to Apple’s Well being app after you join it, permitting you to take your health knowledge elsewhere. And for those who’re not close to a related gadget, the H10 has a small quantity of onboard storage, permitting you to log a exercise even with out your units current.

Observe: We have seen a number of customers run into a difficulty the place the H10 seems on the iPhone, however not the Apple Watch. To repair this, you may wish to pair the H10 to the Apple Watch first earlier than connecting it to your iPhone — or disable Bluetooth in your iPhone from the Settings app earlier than trying to pair with Apple Watch.

Polar’s H10 was by far essentially the most correct of the health trackers I attempted, nevertheless it does come on the expense of getting to put on a chest strap. Throughout a run or weight coaching session, this should not hassle you, however full-contact sports activities could be a bit a lot: For me, something strapped to my chest in derby is a possible bruising hazard — and I’ve seen sufficient cracked sternums to wish to keep away from that destiny in any respect prices. So if you will get previous the truth that this needs to be worn round your chest, then it may be thought-about one other top-of-the-line exterior coronary heart fee screens for Apple Watch.


  • Correct readings
  • Syncs with Well being app
  • Onboard storage


  • Chest strap type
  • Unhealthy app design

Greatest for Accuracy

Polar H10 Heart Rate Monitor strap

Polar H10 Coronary heart Fee Monitor Chest Strap

Polar’s know-how supplies speedy health monitoring.

This water resistant chest strap is snug and provides electrode-based coronary heart monitoring, so it is extra correct than others.

Greatest for Runners: Scosche Rhythm24

Scosche Rhythm 24Supply: Scosche

The Rhythm24 has a battery standing indicator, so you may know if it is time to recharge.

It has seven completely different monitor modes for various coaching choices. Set it for working, biking, swimming, simply monitoring your coronary heart fee or coronary heart fee variability for figuring out stress and restoration throughout coaching. If you happen to’re coaching for a duathlon or triathlon, set one of many multi-modes, and it’ll monitor every of your completely different actions.

You possibly can file your exercise and save your coaching knowledge to know higher the place you want enchancment.

Just like the Rhythm+, which remains to be the perfect exterior coronary heart fee monitor for Apple Watch, it makes use of each yellow and inexperienced optical sensors to raised accuracy with all pores and skin tones.

I examined the Rhythm24 with day by day working periods alongside my Apple Watch. I discovered that the Rhythm24 was all the time extra correct, monitoring each heartbeat in real-time as an alternative of updating with new data that was already behind by the point it synced.

The Rhythm24 makes use of the identical kind of armband used with the Rhythm+. I discovered it very snug throughout my runs however haven’t tried it with weight coaching workouts.

For only a bit greater than the Rhythm+, the battery life and a number of coaching modes make this a significantly better match with health followers that exercise for extra than simply an hour or two. If you happen to’re a long-distance runner, a triathlon coach, or simply wish to monitor your coronary heart fee all day lengthy, get the Rhythm24.


  • Water resistant
  • Longest battery life
  • A number of exercise modes
  • Assist for triathlon coaching

Greatest for Runners

Scosche Rhythm24

Scosche Rhythm24 – Waterproof Armband Coronary heart Fee Monitor

Nice for health buffs which might be in it for the lengthy haul.

This coronary heart fee monitor armband has 13 hours of steady reminiscence storage, so depart your telephone behind while you’re coaching.

Greatest for Coaching: Garmin HRM-Tri Coronary heart Fee Monitor

Garmin Hrm Tri External Heart Rate MonitorSupply: Garmin

Once you’re coaching exhausting, you need an exterior coronary heart fee monitor that will not get in the best way. The Garmin HRM-Tri is among the smallest and lightest coronary heart fee monitor choices from Garmin, and it’ll stay snug all through your coaching.

With the HRM-Tri, it is designed to greatest deal with working, biking, swimming, and lots of extra intensive actions. The monitor makes use of a single CR2032 battery that may last as long as 10 months for those who simply do an hour of coaching a day. The HRM-Tri even supplies suggestions in your working kind and working dynamics because of the accelerometer that measures torso motion when working.

As you employ the HRM-Tri, it could actually retailer as much as 20 hours of coronary heart fee knowledge out of your swims and coaching, and this knowledge might be forwarded to different Garmin sports activities watches after your session. Or you’ll be able to simply ship your knowledge on to the Garmin Join app to view your swim metrics, coronary heart fee graphs, tempo, stroke, and extra.


  • Small and light-weight
  • Comfy to put on
  • Lengthy battery life
  • Provides suggestions on working kind and dynamics
  • Nice for swimming


  • Requires CR2032 battery
  • Not rechargeable

Greatest for Coaching

Garmin Hrm Tri Heart Rate Monitor Render

Garmin HRM-Tri Coronary heart Fee Monitor

Designed for triathletes

The Garmin HRM-Tri is a snug coronary heart fee monitor that’s good for coaching whereas working, biking, or swimming.

Greatest for Cyclists: Wahoo TICKR FIT Coronary heart Fee Monitor Armband

Wahoo TICKR FITSupply: Wahoo

If you wish to have the guts fee monitor that champions like Staff INEOS, Bora-Hansgrohe, Katusha Alpecin, Ironman World Champion Jan Frodeno, Heather Jackson, and American Professional Mountain Biker Sonya Looney, then try the Wahoo TICKR FIT.

The TICKR FIT is an armband that works greatest in your forearm, and you will get personalised coronary heart fee coaching for extra environment friendly exercises. With TICKR FIT, you may monitor and seize your coronary heart fee in real-time, see your coaching zones and energy burned in your iPhone by over 50 appropriate apps because it makes use of Bluetooth/ANT+. This implies it would work with not solely your iPhone however tablets, GPS watches, and bike computer systems by Wahoo, Polar, Garmin, Apple, and lots of extra.

If you happen to use the Wahoo Health app with the TICKR FIT, you’ll be able to mechanically add that knowledge into your most well-liked coaching platform of selection, like Strava. And whereas it appears geared extra for biking, the TICKR FIT works properly with any type of train. The TICKR FIT is kind of correct, snug, and stays in place as you train.


  • Comfy on the forearm
  • Correct readings
  • Works with over 50 apps and lots of units
  • As much as 30 hours of battery life
  • Reasonably priced price ticket


  • No knowledge saved on the gadget itself

Greatest for Cyclists


Wahoo TICKR FIT Optical Coronary heart Fee Monitor Armband

Champion cyclists use this coronary heart fee monitor

TICKR FIT is snug and safe. It really works with over 50 apps and connects to most units for a customized expertise.

Why hassle with an exterior coronary heart fee monitor?

Coronary heart fee monitoring on Apple Watch comes on the expense of battery life: The smartwatch’s well being sensors account for a big majority of battery drain. As such, Apple limits how often the sensor records data, even throughout exercises. At relaxation, you may get coronary heart fee knowledge each 10 minutes. Throughout exercises, you are prone to get recordings each 10 seconds to a minute.

The wrist-based monitor also can get tripped up for those who are likely to do many workouts involving wrist bending or fast motion. The oximeter works by measuring the motion of your blood utilizing mild. Once you flex your wrist, you’ll be able to momentarily change that circulation, resulting in inaccurate coronary heart readings (If you happen to’ve ever seen an Apple Watch studying of “65bpm” or decrease or a grey quantity while you’re in the midst of a high-intensity exercise, that is seemingly what has occurred).

If you happen to’re anxious about your Apple Watch’s battery life throughout a prolonged exercise (like a marathon, as an example), otherwise you’d like extra constant and fast readings, contemplate an exterior coronary heart fee monitor. These Bluetooth equipment usually run off fast expenses or watch batteries and supply sooner readings from a location with higher circulation (just like the chest or higher arm). If you do not have an Apple Watch, you should utilize exterior screens together with your iPhone to get beneficial coronary heart fee knowledge.

We have examined a number of of those Bluetooth coronary heart fee screens to provide the greatest suggestion, and the Scosche Rhythm+ Monitor Armband is the perfect exterior coronary heart fee monitor for Apple Watch.

Get match with the perfect exterior coronary heart fee monitor for Apple Watch

The Scosche Rhythm+ monitor armband is the perfect exterior coronary heart fee monitor for Apple Watch as a result of it’s a dependable, correct, and inexpensive monitor that is good for amateurs and health fanatics alike. Not solely that, nevertheless it’s additionally an attention-grabbing accent that is sure to show heads when you work up a sweat.

Plus, it is considerably extra snug than sporting a chest strap throughout heavy-duty exercises whereas being about as correct. The Rhythm+ makes use of inexperienced and yellow oximeter sensors (described as “PerformTek biometric sensor know-how”) to get a extra exact take a look at your coronary heart fee than the Apple Watch’s inexperienced sensors alone and data knowledge way more steadily. The primary era of the Rhythm+ has Eight-hour battery life, however Scosche went additional and made the Rhythm+ final 3x as a lot, so you will get 24 hours of exercises earlier than having to plug it again in. And one other beauty of Rhythm+ is the truth that since Scosche does not have its personal devoted app, your knowledge simply syncs instantly with Apple Well being — no different app wanted.

Credit — The crew that labored on this information


Christine Romero-Chan is a Employees Author at iMore attempting her greatest to get again right into a extra energetic way of life. She has been testing out new units and instruments that may assist get her again on monitor.


Lory Gil is the previous Managing Editor at iMore who picked up the health mantle rather than Serenity, however she now works for Apple. She’s been testing coronary heart fee screens on her day by day morning jogs to verify they meet our highest requirements.


Serenity Caldwell was previously the Managing Editor at iMore, and now works for Apple. She spent a yr testing these coronary heart fee screens whereas figuring out, coaching for curler derby, and testing her physique’s limits.

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