Heart Rate Variability – How to Use It in Your Training

By Jiri Kaloc

Changes in heart rate variability say a lot about how well you’re handling stress, and that includes your training. HRV can help you see whether you’re well recovered and ready to take on high intensity or if your body needs more rest to catch up. But can you actually use HRV to guide your training decisions?

How HRV responds to training?

Studies show that strenuous exercise leads to a lowering of HRV. They also show that with sufficient rest and recovery, heart rate variability rises again. This relationship between training and HRV is very important for any cyclist considering using HRV for training. So, how can you use this information in training?

You can train smarter with HRV

In theory, HRV should allow you to modify your training plan based on what your body can handle. Having a predetermined training plan is important, it gives your whole season a structure and ensures you will cover all your bases. HRV is layered on top of it. If your HRV is low and your next session should be high-intensity intervals, you should include a recovery ride and move the intensity to the next day. And, similarly, if your HRV is high, you know you can push extra hard in training and you’ll bounce back quickly. It should help you train smarter, at least in theory.

Training Ride
Measuring HRV can reveal a lot about your health, lifestyle, and training. You can use HRV to track improvements in all of these areas. © Profimedia

Using HRV helps improve performance

Researchers from Miguel Hernández University and Stellenbosch University decided to test whether HRV can actually be used to guide training sessions and lead to better outcomes. They recruited 17 cyclists for their study and after 4 weeks of standardized training, they split them into two groups.

  • Typical training group: For 3 weeks, cyclists would ramp up intensity followed by 1 week of rest. They would do this twice for a total of 8 weeks.
  • HRV-guided training group: Cyclists would train for 8 weeks and the intensity of training would be decided by their HRV. But they would never do more than 2 consecutive days of high intensity or rest.

What the researchers found at the end of the experiment was that the HRV group spent significantly less time training at a moderate intensity but more time at low intensity. Both groups spent about the same time at high intensity. And as to their performance? The HRV-guided group did a lot better compared to the typical training group.

  • 5% greater increases in peak power
  • 14% greater increases in power at ventilatory thresholds VT2 (highest intensity sustained for 30 to 60 minutes)
  • 7% greater increases in power over a 40-minute time trial

The authors concluded that these improvements may be thanks to the fact that the HRV-guided athletes were more ready for their high-intensity sessions and also because they spent less time at moderate intensity. Overall, this is great news for every cyclist tracking HRV.

Training is not the only thing impacting your HRV

It might be tempting, after reading the results of that study, to jump on your HRV data and adjust every training session based on them. You have to keep in mind that there are other things that influence your HRV. In the previous article, we discussed how your lifestyle, sleep, work stress or diet can all contribute. Training is not the only thing you can adjust. And it’s equally important to be aware of how you feel. Just like you shouldn’t be a slave to your power numbers, don’t be a slave to HRV.

Using resting heart rate with HRV

Once you get used to tracking and interpreting HRV, you can combine it with resting heart rate (RHR). This can help you zone in on how your body is doing even better. Just keep in mind that these are not hard rules, just general observations from athletes who have been using HRV.

  • An increase in HRV coupled with a decrease in RHR is a sign you’re reacting well to training and you’re ready for more.
  • An increase in HRV coupled with an increase in RHR signals you are accumulating fatigue unless you’re at the beginning of a training block.
  • A decrease in HRV coupled with an increase in RHR also signals fatigue unless you’re tapering, in which case it’s a good sign that you’re ready to perform.
  • A decrease in HRV coupled with a decrease in RHR is a sign of prolonged low-intensity high-volume training. Rest should reverse the trend, if not, it’s a sign of overtraining.

Equipped with all of that data, you’re sure to get the most out of your intervals and sprints. And maybe you’ll even take that extra rest day when your body asks for it.