What is heart rate variability?

October 08, 2019 4 min read

What is heart rate variability?

It’s all too easy to convince yourself that you feel ready to ride, or ready to race when you actually feel lousy, your stressed and you didn’t sleep well. This can be something that really effects amateur elite athletes because pushing and going hard even when you don’t feel like it can lead to fantastic results (sometimes). 

You also might not want to let your team or riding buddies down, or maybe you just need to let off some steam and do something you love after a stressful week. 

The thing is if you are overtraining and pushing yourself when you need to rest you won’t be able to reach your peak fitness or power. You also risk injury, which is going to affect your performance in the short and long term. So, yes you need to be motivated to improve and continue to your training, but only if you are not at breaking point and in need of a well earned rest. 

So how do you know what your most beneficial course of action is; Hard ride or get a massage? Luckily there are heart-rate tracking apps that can help you out. 

Recovery and training tracking apps give you a reading based on your hearts electrical patterns, measuring not just when your heart beats, but how often it rests. 

If you are not getting enough sleep, stressed about home life or work, or been on a bender the night before, the data will show up in front of you as a low count, making it harder for you to ignore your body’s needs and push through. 

Heart rate variability 

Heart rate variability takes over from using resting heart rate (RHR) as an indicator of overall health and fitness for training purposes. This is because heartbeats are not regular. A RHR of 60 beats a minute is not 1 beat a second, there are frequencies and variations to these frequencies that can be measured. 

The measure of heart rate variability (HRV) is the microsecond between the rest peaks in the heart’s electrical patterns. A high HRV (i.e. 90 - 110) can indicate when a person is well rested and ready for a hard training session. A low HRV (i.e. 30-40) can mean a person is in need of a rest due to training stress, life stress, poor diet, poor sleep quality or the consumption of caffeine or alcohol. 

How to measure your heart rate variability

There are a number of apps which can track HRV for you, typically they also track other recovery based metrics like the duration and quality of your sleep to give you a complete picture of your health.

You can track your heart rate variability without much equipment, depending on the app you use. Some (like Whoop) connect to data from a wristband monitor while others (like WattsonBlue) use your phone camera to measure your HRV. 

To use HRV effectively, you need to build up a data bank of info to determine your baseline figure. The baseline is your medium, for when you are healthy and everything is going okay. When you have this you can determine if your rates are higher, your green light to really push hard, or lower, a really good reminder to put your feet up and take it easy today. 

It’s also a good way to pinpoint the effect different activities have on your health. You can take measurements after eating certain foods, having alcohol or being ill to see what impact these events and others have on your HRV numbers. 

Every person is different so the accuracy of the readings is gained by comparison to your baseline rather than comparison to a ‘correct’ number or other people. 

As well as your HRV measurements you need to factor in how you feel, how motivated you are, and your cycles of power and rest to decide if you skip a training session or power on. The good thing is that with consistent monitoring you have a reliable gauge to remind you to rest and maintain a healthy life-balance. 

Variables to the variability 

To collect the data accurately you need to build the measurements into your routine consistently. There are a number of things that can influence heart rate variability and therefore make your data inaccurate.

It’s best to take your baseline readings at the same point in your day, every day, to avoid confusing the data with external influences and mixing in variables. For ladies as well there are factors to consider with menstrual cycles that can influence HRV as well 

Morning is better than night, when you might be fatigued, but not as soon as you wake up because this can be a time when you are highly alert and stimulated. It’s best to take time to relax, sit and settle in before you take your measurements. Taking a reading while having a conversation or reading news headlines can also throw off your benchmark if you are excited, stressed or agitated during these activities. 

Factors that can throw off your data collection and make results inaccurate and unusable: 

  • Caffeine
  • Alcohol
  • Recently taking a shower or bath
  • Excitement
  • Agitation
  • Stress
  • Having just woken up
  • Missing a day of taking measurements
  • Straight after drinking large amounts of water
  • Recent exertion
  • Some foods, like sugar 


These studies are new and these apps have only come on board in the last few years so there is a long way to go before studies and testing can give us a better indication of how accurate HRV is. As far as word of mouth goes from those who use it say, HRV is a much better reflection on your levels of rest and recovery compared to resting heart rate. 

When you have an accurate baseline then it is useful to take measurements to determine when you are ready for an intense session and when you are in need of a rest or quieter ride. 

Keeping your heart fit and strong for life on and off the bike? That’s freedom!

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