With all the attention given to power meters in recent years, you’d be forgiven for thinking that heart rate monitors have vanished. Not so, and they’re still a useful training aid.
A heart rate monitor, as the name suggests, measures your heart rate in beats per minute and displays it on a screen. As you’ve no doubt noticed, the harder you ride, the faster your heart beats, so heart rate is a useful proxy for your effort level.
You can therefore use a heart rate monitor as a training aid, setting target heart rate ranges for training sessions. Some monitors record your heart rate every second for later examination and may also estimate the Calories you’ve burned, useful if one of your cycling aims is to lose weight.
Heart rate’s not a perfect measure of riding effort though. It can be affected by the time of day, caffeinated beverages, the weather and how tired you are. But with that in mind, it’s still useful, and a heart rate monitor costs a lot less than even the cheapest of the new wave of power meters. The more sophisticated units will work with a power meter too, so you can upgrade to training with power later if you get more serious.
Traditional heart rate monitors use a sensor strap round your chest to pick up electrical signals from your heart as it beats; this is still the most accurate way to measure heart rate outside of a laboratory
Some heart rate monitor watches use an optical sensor at your wrist, which is comfier than a chest strap but not quite as accurate
Many cycle computers will measure heart rate if equipped with a compatible sensor
As you go up the price range you get additional features like satellite positioning to measure distance and speed, programmable workouts and lots more
Most sport-orientated heart rate monitors work the same way: a sensor band round your chest detects the heart's electrical activity and transmits pulses to a device with a screen that does the spade work of calculating and recording your heart rate. It's the same principle as a hospital electrocardiography (ECG) machine. In the last few years wrist-mounted fitness trackers have appeared that shine a bright LED into your skin and detect your pulse by the change in the reflected light as blood fills and drains from the capillaries, a process called photoplethysmography. This isn't as accurate as ECG.
The device providing the read-out could be a watch or a handlebar-mounted computer or GPS unit. It might also be your mobile phone; many heart rate monitor bands now use low-power Bluetooth Smart that will communicate directly with a phone, or you can add an ANT+ dongle to your phone to work with a compatible band.
At the cheaper end of the price range are standalone heart rate monitors, almost always built into a watch. They’re easy to use and if you do more than one sport they’re the most versatile way of measuring heart rate. The more you spend the more features you get and the more the device or its associated applications will do for you, including working out your heart rate zones and warning you if you’re going too hard or too easy on a given session.
Cycling-specific heart rate monitors roll the function into a computer or, if you’re spending a bit more, a GPS unit. More advanced (that is, expensive) units log your ride and heart rate data so you can see how much time you spent in each of your heart rate zones and compare segments from one ride to another to measure your progress. For example, if you’re faster up that hill for the same heart rate, then your fitness has improved.
All of this means you have a huge range of choice in devices that display and record your heart rate, to the point where the importance of this function has been over-shadowed by all the excitement about GPS-enabled exploring and bagging Strava segments. Nevertheless, if you’re aiming to get fitter, it's the core function you want whether you’re spending £30 or £300.
It's a general-purpose cycling GPS and training aid and you'll need to buy a sensor to get your heart rate on it, but the Karoo 2 might nevertheless be the best all-round cycling dashboard you can buy. One feature that helps it earn that title is its ability to display a nifty graph of the percentage of your ride you've spent in each heart rate zone, rather like the power zone graph in the above pic.
If you take part in triathlons or other multi-sport activities, then this is the GPS & heart rate watch for you. The Rival watch detects when you change from, swimming to running or running to cycling and automatically starts a new split. It can also change the units it displays speed and distance in if you're more comfortable with miles on the road and metres in the pool. Fiendishly clever.
The 4iiii Viiiiva, works well as a heart rate monitor (HRM), but there's more to it than that: rather than simply being an ANT+ or Bluetooth unit, it integrates both and also acts as an ANT+ bridge. That means it can take the signal from your ANT+ speed sensor or cadence sensor and send it to your Bluetooth-only phone. 4iiii also claims its heart rate measurement is more accurate and faster to respond than other heart rate straps.
The Mio Velo measures your heart rate from your wrist and sends it to other devices via both Bluetooth Smart 4.0 and ANT+. It can also take data from other ANT+ devices – a speed and cadence sensor, for example – and re-transmit it using Bluetooth Smart, allowing you to link ANT+ sensors to a non-ANT+ smartphone.
The Mio Velo comprises a silicone strap containing a 46mm x 25mm x 10mm working unit. Ours weighed just 35g. It takes your heart rate via LEDs and an 'electro-optical cell' that monitors the volume of blood under your skin. Mio boast a 0.99 correlation to electrocardiogram in laboratory testing. In other words, they claim that it is highly accurate.
The TICKR FIT uses an optical sensor and goes on your arm. It's accurate and comfortable, and it might be just the thing for indoor training, or if you don't like chest-mounted heart rate monitors for whatever reason; our non-scientific polling suggests that there's a fairly small but not insignificant minority of people in that camp.
The TICKR FIT is rechargeable, and comes with its own charging cable which attaches magnetically to the sensor. Having a proprietary charger means you'll need to remember where the lead is, and you can't charge at work if the lead is at home in your drawer of useful things, but you shouldn't need to charge it that often. Wahoo claims a battery life of 30 hours, which should see you through most rides you'd reasonably need a heart rate monitor for. If you're doing a two-day sleep-in-a-hedge audax, your heart rate is probably the least of your worries. In testing we found the battery life to be very good, although not quite up to the 30-hour claim.
If you have an iPhone or Android 4.3 device, this Bluetooth Smart heart rate strap will pair with it, so you can add heart rate data to your Strava logs. It has ANT+ capability too, so you can add heart rate measurement if you have a compatible bike computer or GPS unit.
One of the cheapest computers with heart rate function and the necessary strap bundled, the CM4.21 can download ride data to your PC so you can keep a record of your rides.
It’s not the cheapest option, but Wahoo’s Bluetooth Smart heart rate strap comes with Wahoo’s own Fitness app that provides training zones for fat-burning and intense training and creates a eight-week training schedule for you. The 2032 coin cell in the strap is good for 500 hours according to Wahoo, and the clever design sees the pod acting as a bridge between the two ends, rather than popping onto sensor pads on the strap itself.
For a bit more money the £65 Tickr X supports multiple Bluetooth connections and has 50 hours of onboard memory so you can use it without a device and transfer your data later. Reviewer Dave Arthur was really impressed.
This inexpensive GPS watch from Decathlon picks up your heart rate using an optical sensor on the back of the watch body, which is more comfortable than strapping a sensor round your chest if not quite as accurate. You can use a Bluetooth chest strap if you want and it's waterproof enough for surface swimming if you fancy a mid-ride dip.
If you want a wrist heart rate monitor with a more sophisticated set of features, this watch from Garmin includes GPS, incorporates some cycling-orientated features, and works with ANT+ and Bluetooth devices.
The Edge 130 Plus is the smallest computer in Garmin's current range, and along with its diminutive size, Garmin has nailed the user interface, which is a dream to use.
If you don't need route mapping and navigation and just want to track all the important metrics like speed, distance, elevation — and heart rate, of course — the Edge 130 Plus does everything you need.
It's bundled with a heart rate strap here and in one of those occasional things online vendors do that make you go 'Huh?' it's cheaper than the bare unit. Grab one before they notice and change their mind..
Despite its very modest price, this base model from Bryton picks up signals from just about every constellation of navigation satellites up there: GPS, Galileo, GLONASS, BDS and QZSS. It has a built-in barometric altimeter and works with Bluetooth LE sensors for speed, cadence and heart rate. Just add a £30 Kalenji heart rate belt and you've got a full suite of modern functions for a very modest price.
Want heart rate, altitude, power and GPS? Polar's M460 provides all that and more, and while it has limitations — it lacks ANT+ connectivity, so your power meter needs to speak Bluetooth Low Energy — it's very good value for its feature set.
This version of Garmin’s benchmark GPS comes with sensors for speed/cadence and heart rate, and Garmin's Cycle Map of the UK.
The Edge 830 is highly customisable, and generally very reliable with enough battery life for all but the longest of epics and the ability to run from an external battery if you’re riding for more than the nominal battery life of 20 hours.
If you can live without the speed and cadence sensors, you can get the bare unit for £310.49; add the Kalenji or Wahoo heart rate straps and you've saved enough for a very nice pub lunch stop.
Garmin's flagship GPS features a 3.5in high-resolution capacitive touch screen that Garmin reckons works in the wet or with gloves, and ambient light sensors automatically adjust the screen brightness to suit the riding conditions. Battery life has been extended to a claimed 24 hours and the Garmin Charge battery pack accessory doubles the run time to 48 hours for longer rides.
Most of the improvements over the Edge 1030 are incremental, but the 1030 Plus does feature a built-in coaching system that'll tell you what sort of ride to do today. Other key features include Trendline navigation using the many activities uploaded to Garmin Connect to provide routes on the most popular roads and off-road trails, backed up by preloaded Cycle Maps for turn-by-turn directions on all terrain with alerts for sharp corners and elevation information. You can also choose from three round-trip suggestions by choosing a distance and starting direction if you want the Edge 1030 Plus to recommended new routes.
It's not cheap, especially at the £599 RRP, but the Edge 1030 Plus is still the daddy.
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John has been writing about bikes and cycling for over 30 years since discovering that people were mug enough to pay him for it rather than expecting him to do an honest day's work.
He was heavily involved in the mountain bike boom of the late 1980s as a racer, team manager and race promoter, and that led to writing for Mountain Biking UK magazine shortly after its inception. He got the gig by phoning up the editor and telling him the magazine was rubbish and he could do better. Rather than telling him to get lost, MBUK editor Tym Manley called John’s bluff and the rest is history.
Since then he has worked on MTB Pro magazine and was editor of Maximum Mountain Bike and Australian Mountain Bike magazines, before switching to the web in 2000 to work for CyclingNews.com. Along with road.cc founder Tony Farelly, John was on the launch team for BikeRadar.com and subsequently became editor in chief of Future Publishing’s group of cycling magazines and websites, including Cycling Plus, MBUK, What Mountain Bike and Procycling.
John has also written for Cyclist magazine, edited the BikeMagic website and was founding editor of TotalWomensCycling.com before handing over to someone far more representative of the site's main audience.
He joined road.cc in 2013. He lives in Cambridge where the lack of hills is more than made up for by the headwinds.