Whilst science evolves and training methods come and go, there has been one constant for the past fifty years: using heart rate data to optimise your approach to training and racing.
The use of heart rate data has gone through quite the journey since monitors were introduced in the late seventies. Their introduction allowed training to be tracked and quantified for the first time ever. To this day it will go down as one of the most important developments in endurance training history.
For cyclists, the recent trend of power meters getting cheaper and cheaper means that heart rate isn't quite as important as it once was. The beauty of a power meter is that it provides instant data and lack external influences that heart rate is so susceptible too.
That’s not to say checking your heart rate isn’t important, rather how we use it has just changed a little…
How do pro athletes use heart rate data?
While many athletes still use heart rate alone to adapt their training, there’s no arguing that the heart rate-power meter combination is what’s best.
Personally, I use heart rate as a reference point against my power; if it’s reading abnormally, then alarm bells go off and I do some more digging.
This case study is from my World Championship ride all the way back in 2018. It was the biggest race of my career to date and it was to be my launchpad into the pro ranks. I had a simple pacing strategy based on power.
That day, my power meter failed. Post-race analysis showed it was consistently reading 50 watts lower. However, my heart rate, which after three minutes of effort had reached where it should be, displayed that I should ignore my power meter.
At the time, you don’t know that your power meter is under-reading. It would have been easy to try to reach my target power, but I’d ultimately have blown up. Instead, I trusted my perceived exertion and my heart rate, and finished in 8th position.
The heart-power meter combination is better than just using one as it allows you to spot abnormalities. A power meter is instantaneous, so will record what is happening second-by-second. Heart rate on the other hand is delayed, which is why it often takes a couple of minutes for your heart rate to settle when doing an effort. The fact that heart rate can also be altered by external factors, such as too much coffee drinking, means having the two metrics is the way to go!
That leads me nicely into... wearables.
The latest buzzword in the world of sport tracking and technology. The two most popular are Whoop and Oura, although there are plenty of similar devices out there. Wearables allow you to track what your body is doing 24/7.
They monitor your body temperature, heart rate, heart rate variability (HRV) and sleep metrics. For athletes of any level, they are a gold mine of information. If those alarm bells start going off, the heart rate data from my wearable is where I go looking first to provide more context.
We spoke to Jeroen Dingemans, a coach of the pro Lotto Dstny cycling team, to see how wearables are utilised in a professional team.
Morning pulse and HRV are monitored on a daily basis. We use this to determine the rider's readiness. If, for example, HRV drops when it shouldn’t have, we know something is not right (maybe incoming sickness), especially when the morning pulse is rising.
On the other hand, sometimes we want to see bad morning numbers, such as when functional overreaching on a hard training camp. It can indicate that training stress on the rider's body is working and we’re building towards a good condition.
Whether it’s to inform training, monitor recovery or as an early sign of fatigue, there are plenty of uses for the good old fashioned heart rate monitor. It’s the first step to doing structured training, and at less than £50, it’s a cheap and accessible way to go into the structured training world.
If you’re a caffeine addict (like seemingly every cyclist in the world!), then the caffeine can impact your data. Same if you’re fatigued, or getting sick. A heart rate monitor is often the first warning sign something is happening; the difficult part can be figuring out exactly what that is.
How do I use heart rate data?
My relationship with heart rate data has developed no end since the start of my cycling journey. A heart rate monitor gave me my first proper training plan, whereas nowadays it’s used as a side metric next to power.
This is not too dissimilar to what Lotto-Dstny told us either:
For training, heart rate is not the first thing we look at. Power output is the primary number that riders follow, but we still look at heart rate in relation to power and it is still monitored like we used to do.
When a rider goes on an altitude camp, endurance training can be set by using a heart rate zone instead of a power zone, especially during the adaptation period. Heart rate will then help to set the right intensity on long easy rides.
There are plenty of stories about people racing to heart rate, and interestingly enough I’m not one of them anymore. When I was younger, I’d often have a self-set heart-rate cap, especially in time-trials. These days, I don’t even have a heart rate on the screen when racing.
It’s thanks to my former coach who told me to stop limiting myself. You never know how you’re going to be on race day, so why set yourself a limit? If you start limiting yourself, there’s potential that you’ll miss out on a personal best performance.
There is, of course, a fine line here. Throwing caution to the wind relies on you knowing your body. I’ve had some of my best performances ever ignoring data, I’ve also blown up spectacularly trying to make an attack and ended up finishing further down than I would’ve done if I’d just been sensible.
Apart from tracking my metrics every morning, heart rate mostly comes into play on my favourite day of the week, rest day. I’ll often do an easy hour on the bike on my rest day; I refer to this ride as “going for a walk with my bike”. The aim of it isn’t necessarily for training, but to turn the legs and get out of the house.
Here’s a little game for you to try…
Go out for an hour’s ride and try to get your average heart rate lower than your average power. This sounds simple, but is actually quite difficult to do.
Whether you’re using heart rate data as your sole training metric, to track day-to-day trends, or simply as a means of measuring just how easy you can go on a recovery ride, they’re most definitely not out of the training picture. So, it’s something you’re going to want to get a solid understanding of if you want to perform at your best
I know the team at PF&H rate Gordo Byrn’s blog, which is a good starting point for this. And Chris wrote a decent piece summarising the pros and cons of different low heart rate training methods (as this is often the context through which athletes are exploring using heart rate data). Andy also wrote an article detailing his experience with using HRV in his training.