The Triathletes Guide to Heart Rate Variability Training (HRV)

What is Heart Rate Variability?

Heart Rate Variability, or HRV for short, is the varying difference of time between heartbeats. You may commonly hear when a heart rate is measured that it’s ‘x’ number of beats per minute, but within that minute the beats will be occurring at varying intervals. This, simply put, is what heart rate variability is and we will look at why triathletes should consider Heart Rate Variability Training (HRV), 

Heart rate variability, or HRV for short, is a measure of your autonomic nervous system that is widely considered one of the best objective metrics for physical fitness and determining your body’s readiness to perform. The Whoop

The body has two competing branches within the peripheral nervous system affecting heart rate, the sympathetic, which is responsive to stress, controlling fight-or-flight, and the parasympathetic which is responsive to relaxation, controlling rest-and-digest.

HRV gives you an insight into whether one is predominating, or if they’re balanced and in this way can be hugely helpful in informing the way you are approaching fitness.

What is HRV training?

HRV training is a practice used by professional astronauts and athletes alike, wherein a resting state at a particular point in the day (usually the mornings upon waking, before eating or drinking), they measure their HRV using a monitor and let that dictate which training would be the most beneficial for that day.

An individual’s HRV changes on a daily basis. Athletes, in particular, want a high HRV because it’s seen as an indicator that their bodies are well adapted, rested and capable of performing at their best in any setting, as a stressed body has little variability between heartbeats.

A low HRV would be a sign to do some light exercise or have a rest day, and a high one a sign to push harder. Although context is required here.

  • An increase in HRV with a decrease in RHR (resting heart rate) generally means an athlete is coping well with training.
  • An increase in HRV with an increase in RHR is generally a sign of accumulated fatigue unless it at the very beginning of a short training block.
  • decrease in HRV with an increase in RHR is generally a sign of accumulated fatigue unless an athlete is tapering and then it could be a positive sign for readiness to perform.
  • decrease in HRV with a decrease in RHR is generally a sign of prolonged low-intensity high volume training and if it cannot be reversed with rest could be a sign of being in an overtraining state.

How can you, as a beginner use Heart Rate Variability Training (HRV) to improve your performance?

Incorporating HRV readings into your training regime as a beginner can offer far greater benefits than if you started using the measurement further along in your fitness journey. Why?

When you’re just starting out you naturally don’t have the awareness of your body and its limits that grows with time. You also don’t have any fixed habits or routines that may make you resistant to the changes proposed by the reading.

If you’re the high-achieving type who tends to always be pushing themselves and never feel like you’re doing enough, using HRV to guide your training takes some of the pressure off. It can make you realise that you need to rest before you overdo it, potentially injuring yourself and setting your goals back. And it validates your efforts over time as your baseline HRV gets higher.

Whereas if you’re the type of person who’s quickly disheartened by the demands of a new sport and prefers to take it easy, giving up miles before reaching your full potential. HRV readings can give you the push you need to go a bit further some days and confirm your efforts on others, letting you rest guilt-free.

HRV training can improve your performance by informing you of how your body responds to particular types of training, and how long it takes to recover, allowing you to better structure your programme and reach your goals more efficiently.

HRV training tips for beginners

  • HRV isn’t always a reflection of the training you’re doing, it can be a helpful indicator of other aspects of your life like hydration, nutrition, sleep, stress and illness. So if a low reading baffles you after a rest day make sure to pay attention to other areas of your life that may need TLC.
  • A high HRV isn’t always a good thing, especially if it’s markedly spiked from your usual baseline, it can be a sign of an elevated immune system or hyper-recovery from training too much. It’s important to note how you’re feeling in your body when you take the readings.
  • And a low HRV isn’t always a bad thing, again, it’s important to put the readings into the context of what’s happening in your life and how you feel. Age and other factors can play a part in individual’s having a naturally lower baseline HRV. And a drop after an intense workout is a sign of a healthy stress and recovery response, as long as it returns to normal.
  • Being consistent with HRV readings is the key to getting the full benefits of HRV training. If you’re not taking the reading at the same time each day, in a resting state and on a regular basis, you’ll struggle to get the important information from it like your baseline and where a day’s reading fits on a general trend. HRV trends are what matter.
  • There’s a wide range of HRV monitors on the market, alongside apps to go with them, to make sure you’re getting accurate readings, check the type of sensor the device uses (ECG/EKG) and that it separately measures RR intervals (the gaps between heartbeats), not just BPM.


Written by – Amy Moretsele