Endurance Skating

Training, Racing & LCHF Fueling For Skating And Endurance Sports

Heart Rate Monitoring: The Beat Is On

As a proponent of MAF and other heart-rate based training methodologies, I take my Heart Rate Monitor – or HRM as we all know them by – pretty seriously, I can tell you. I have been known to wear my HRM strap for days at a time, and have even managed to accidentally trigger the metal detector machine at Airport Security thanks to my reluctance to part with my HRM device…

HRMs these days come in a bewildering array of shapes and sizes, with all sorts of extra features, some of which are superfluous, and some which will be very useful, depending on what you want to get out of it. While this article is not intended to be a buying guide for HRMs (there are plenty of places you can read reviews), I will write about my experience with the HRMs systems that I have own so far, and the advantages and disadvantages of each.

Technology Arms Race

Once upon a time – and not that long ago as it happens, – it used to be pretty straightforward. HRMs were standalone devices from companies like Polar or Garmin that came as a 2-piece solution; a chest strap that would pick up the electrical impulse from your heart beat, and transmit the data to a wrist-mounted device, which would display (and if you were lucky enough record) your heart rate data – instant heartrate biofeedback. Then the forces of free market capitalism and technology went to work and we got innovations galore. The most useful development was the addition of GPS technology to offer an integrated HRM/GPS solution. This leveraged both  of these  technologies in a perfectly complementary way, so now you had information not just about the input – ie your work rate as measured by heart rate, but also the output – ie time, distance & pace. This was genius.

Now at the same time as this was happening in the standalone HRM/GPS/Sportswatch market, Smartphone technology was rapidly progressing. A few years ago a smartphone using G3/GPRS would have great difficulty being able to accurately track a cycle or a run through an urban area – for example, I remember taking my Garmin on a typical LFNS which would easily be able accurately be able to trace the route – right down to being able to see where I would place myself at junctions to block traffic, but the same route overlay recorded on a smartphone would be literally all over the place as the mobile data services would simply not be able to cope with the require level of accuracy – we are talking whole streets out! But progress in smartphone and mobile network technology progresses at a staggering rate… G3 and G4 data networks became standard, Blutooth Smart and Location Based Services (LBS) became standard and widely supported. Today, the “Location Based Services” on a smartphone is, to all field-testable limits, just as accurate as the standalone GPS system. A Blutooth HRM paired with Smartphone combo solution provides a very viable alternative to even the most advanced and expensive standalone unit – the Blutooth HRM providing feeding a commecial tracking app such as Strava or Runmeter with heart rate data. The apps are so feature rich that they actually typically exceed the amount of configurable options that a standalone unit will offer, and usually a fraction of the price – the software is infinitely upgradeable, as well as easier and more more practical to upgrade do than a firmware upgrade for a traditional unit. And of course, the beauty is that your HRM will work with just about any of the popular Apps! Don’t like Strava? Try Endomondo, or RunKeeper, or MapMyRun… or any number of other alternatives.  Today, standalone HRM/GPS devices and smartphone apps have a large overlap of functionality and to all intents and purposes vie for the same usage in the weekend-warrior’s biofeedback toolbox.

Pulse Oximetry: Gimmick or Breakthrough?

Despite the invaluable feedback they provide, many people and athletes are still put off by training by heart rate using a HRM, and one of the most commonly cited reasons is the impracticality of the chest strap. HRMs were always, until recently, a 2-piece solution – ie chest strap + display/recording device, whether that recording device was your wrist-mounted display or your smartphone.

However in the last 12-18 months we have seen single-piece strapless HRM devices coming onto the market. These devices sit on your wrist and display the data like a traditional watch, but instead of using a chest-strap to take your heart rate, it uses sensors mounted directly on the back of the watch, using “Pulse Oximetry” technology. For some people – noticeable those with boobies – being able to do away with the chest strap is something of a Godsend.


Personally I own not one, not two, but three HRMs – a traditional HRM/GPS standalone (Garmin 110), a Blutooth chest-strap (Polar H7), and one of the new once-piece wrist-mounted devices (Mio Alpha). The Mio Alpha is the newest model, and now that I have had plenty of opportunities to compare it to the other two HRMs I can say that all 3 solutions have their advantages and disadvantages.

Garmin Forerunner 110 GPS Watch & Chest Strap HRM

I’ve had this for about 4 years now. It’s a traditional standalone HRM/GPS unit, and I retails for around £100 these days. There aren’t too many bells and whistles on it, but it is a trusty solution that does what it says. The Garmin gives good accuracy once it has located your position, and the heart rate reading compares almost identical to the Polar H7 chest-strap, so is presumably highly accurate. Once you have recorded a session, you need to download it to your computer by means of a propriety USB cable, and upload it to Garmin’s online portal, GarminConnect. In fairness, this is pretty good, and they have even recently opened the API up so that new uploads can be automatically synced with your Strava account. The newest models have Blutooth and Wifi connectivity so that they are smartphone compatible. These provide the best of everything – providing the data to your smartphone for use with any app you want, as well as recording the data one the watch itself and using the connectivity of the smartphone (or a Wifi network) to upload the data to GarminConnect without having to wait to connect it to your PC… however they are expensive.

When using the watch for running it is fine, but as a skater the big disadvantage that I have personally found (I would like to hear if many others have experienced this also) is that the chest-strap has very limited range and the reading will often be dropped if you hold your hands behind your back – as speed skaters tend to do. If you bring the watch back around to the front of your body then it can take a few seconds to pick up the chest strap and display the heart rate again.

Key technologies
ANT+
EKG
Global Positioning System (GPS) only
GarminConnect online

Pros

+ Works as a standalone GPS system with optional HRM recording
+ Good HRM accuracy (when it is not dropped)
+ On-wrist display

Cons

– No smartphone compatibility
– Requires propriety cable for charging and data upload to GarminConnect for analysis/summary
– ANT+ chest strap has poor range; HRM data is often dropped when skating with hands behind back

Polar H7 Blutooth Chest Strap (& Mandatory Smartphone)

This is the only solution that requires a smartphone to be useful. The Polar H7 chest strap doesn’t store or display its own data, so needs to be paired with another device that will do so. All the usefulness and flexibility of this solution is built in the smartphone app itself rather than coming from the chest-strap.. and as I have already alluded to the Apps these days are very good indeed. I personally use it with Runmeter and have the app configured not just to record heart rate and GPS data, but also to provide real-time announcements about these metrics at pre-set intervals (in my case to announce heart-rate every minute and average speed at every km marker). It’s this sort of wonderful configurability that I love about this solution.

Very significantly also, if (like me) you like to record HRV, then this is the only device (of the 3 I am writing about) that will do this. For this alone, it’s worth spending the very modest £50 or so to buy, even if you prefer one of the other solutions for normal training usage.

Another plus point for the Polar H7 is that it is the only device of the three that is “Gym Link” compatible – this will essentially display your HRM data on many compatible gym machines such as treadmills and exercise bikes that have the ability to receive the broadcast data. It was a pleasant surprise to me to find this the first time I went into the gym wearing the H7 HRM!

Lastly, in direct contrast to the Garmin solution, the Polar H7 has excellent range – the Blutooth will work from at least 20 meters away and is pretty good even if there are walls or other objects in the way.

Key Technologies
BlutoothSmart 4.0, Gym Link
EKG
Positional Data: Smartphone Location Based Services
Blutooth 4.0 compatible apps – Strava, Runkeeper, Runmeter

Pros

+ Good HRM accuracy
+ Cheapest solution for most people
+ Blutooth standard is compatible with lots of popular Smartphone apps
+ Only solution that works for HRV
+ Good Range; no cutouts
+ Excellent battery life
+ Gym Link feature is a neat bonus

Cons

– No on-wrist display; requires a Blutooth Smart device (eg iphone)

Mio Alpha Strapless HRM (& Optional Smartphone)

The Mio Alpha is my latest acquisition. It shares similarities with both a standalone unit and a Blutooth cheststrap. The USP of the Mio Alpha is its use of pulse-oximetry technology to detect your heart rate without the need for a separate chest strap. It sits on the wrist and displays your heart rate. It has some basic functionality on the watch itself – upper & lower heart rate zone, and a timer function that will record the duration of your workout, average heart rate, and the amount of time you spent within your target zone. There is no GPS on this device, but similar to any Blutooth cheststrap, you can pair it with your smartphone to combine and use it with any phone app.

In use, the Mio Alpha gives you the useful advantage of being able to quickly glance at your wrist to instantly read your heart rate. However, as with all new technologies you have to scrutinize if it actually does a better job of it’s raison d’etre than already proven technology, and after several hours of use it quickly becomes apparent that pulse-oximetry technology is just not as responsive and accurate at recording heart rate as a chest-strap that directly records EKG activity. For steady-state workouts this may not be much of an issue, however if you are doing a workout such as intervals or hill repeats where your heartrate with be operating a wider range, then the lag will be a problem. A secondary problem is that the watch needs to be reasonably tightly fitted or it can easily slip from your wrist and give very obviously inaccurate readings. I have found this is especially true when you are cycling on rougher roads. People with slender wrists might find it a particular problem.

Furthermore, even though it is smartphone compatible, the Mio Alpha is NOT suitable for use with any HRV apps such as SweetBeat. The reason, I’m reliably informed, is that the technology cannot detect the inter-beat R-R intervals of your heart. For me, this is a massive drawback, and it means that no matter how good or feature-rich this type of watch might become, I won’t be ditching my chest strap HRM any time soon.

Despite these drawbacks, the Mio Alpha is a great piece of kit and probably the most convenient solution I own as a pure HRM. It can be used as a one-piece HRM only device, or paired with your phone for a HRM/GPS solution with immediate on-wrist display.

Key Technologies
BlutoothSmart 4.0
Pulse Oximetry
Positional Data: Smartphone Location Based Services
Blutooth 4.0 compatible apps – Strava, Runkeeper, Runmeter etc

Pros

+ Convenient, strap-less technology!
+ On-wrist display
+ Works as a standalone HRM or together with a smartphone
+ Blutooth standard is compatible with lots of popular Smartphone apps
+ Good Range
+ Decent battery life (30hrs)

Cons

– Pulse oximetry technology is laggy & slightly less accurate than direct EKG monitoring
– Doesn’t record heart R-R intervals – useless for measuring HRV 😦
– Standalone device is feature-lite

Test 1

Here is a comparison between the Polar H7 and the Mio Alpha over a 25 minute recording period where I just took a walk around, broke into the odd jog, and climbed up a flight of stairs. The traces do not compare very similarly, with the Mio being laggy and less responsive.

Test 1 - Mio Alpha heart rate trace

Test 1 – Mio Alpha heart rate trace

Test 1 - Polar H7 heart rate trace

Test 1 – Polar H7 heart rate trace

Test 2

This is a trace of the Bacchus Half marathon from both the Garmin & the Mio Alpha.  Here you can see that when it comes to more steady-state workouts the Mio copes better and the traces look more similar.

Test 2 - Bacchus Half Marathon  Mio Alpha Trace

Test 2 – Bacchus Half Marathon
Mio Alpha Trace

Test 2 - Bacchus Half Marathon  Garmin 110 Trace

Test 2 – Bacchus Half Marathon
Garmin 110 Trace

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One comment on “Heart Rate Monitoring: The Beat Is On

  1. Jonathan
    November 18, 2014

    Cheers for info, been meaning to ask you about this..
    🙂

    Like

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This entry was posted on October 20, 2014 by in Equipment and tagged , , , , , , , , .
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