What is HRV and why you should be tracking it ?
Why measure my Heart rate variability (HRV) isn’t it just adding more data to the pile that will take ages to sift through and really at the end of it will yield no real-world results. If this is what comes to your mind, then I am asking you to forget it. HRV is an excellent tool that can be used to track on deep down personal level how you are responding / adapting to your training plans and weather or not your placing too much stress on the body. HRV gives you a deep insight on how lifestyle stressors are negatively impacting your health and performance too. Measuring your HRV will give you back more control of your life and body, knowing when to push hard and when to ease of, maximizing your performance.
What is HRV and why you should be tracking it ?
What is HRV
Heat rate variability (HRV) is a measure of the balance between the ic and the sympathetic nervous system. HRV specifically measures the variation of the time gap between each individual heartbeat (RR interval). HRV can be used as biomarker for homeostatic capacity (capability of systems to self-stabilize) as well as a broad measure of overall fitness and health. HRV can also use to identify injury risk, health risk and potential lifespan. Essential HRV is a measure of how well you are dealing with stress.
Low HRV score
Typically, a low HRV is undesirable as it indicates sympathetic nervous system (fight or flight) dominance, and can be associated with an increase in injuries, inflammation, stress and disease. Low HRV may also suggest anxiety, depression or other health concerns and indicates a priority /need for rest, sleep and recovery
High HRV score
On the other hand, a high HRV is associated with activation of parasympathetic nervous system (rest & digest), relaxation and equanimity. A high HRV indicates that your body has good homeostatic capacity and can recover easily from the stressor’s of life.
Simply put a low HRV is short means your body can’t handle stress to well, whereas a high HRV means your body can deal with whatever stress in thrown your way.
There the main purpose of using HRV is to assess and make the most informed decision about your training that day. It seems form the evidence base to be a constant trend that individualizing your own high intensity training when you as an athlete are in an optimal state of cardiac autonomic homeostasis (well rested), will allow you to maximise the adaption that will be stimulated from those exercise bouts leading to adaptive responses and most importantly performance gains.
What can I measure my HRV with
We are very luck nowadays that we have such easy and affordable access to testing equipment right at home at are very fingertips. There have been tremendous leaps in HRV testing technology from the first publications back in the 70s.
Historically, HRV has been measured using an electrocardiogram (ECG), where you would have to pop into a lad to get your HRV tested or in a hospital setting. Now we have access to smartphone applications combined with a heart rate strap, or a finger-wave pulse sensor.
What you need to test yourself.
You can measure your HRV with various sensors. From a practical standpoint we can use either chest strap heart rate monitors (Polar H7 OR H10) or optical sensors that use your phone camera to take the measurement (HRV4Trainign is the only validated app currently for this)
Heart rate strap
When using a heart rate strap to measure HRV two recommend heart straps to use are Polar 7 OR H10. You can connect using Bluetooth to HRV monitoring apps. Once you’ve got a heart rate strap sorted you will need to connect to an HRV app. One I would highly recommend for this is Elite HRV. The app is compatible with any heart rate monitor that accurately measures R-R intervals and has Bluetooth 4.0.
Optical sensors – Apps
In terms of using other methods to test and track HRV instead of using a heart rate monitor you can go down the route of optical sensors, where you use the camera on your smart phone to take your HRV recordings. However please not that there has been only one app to date that has been tried and tested on athletes in lab-based setting and has been shown to be reliable and accurate and that’s HRV4Training. Or you can use other optical sensors using a secondary piece of equipment such as Corsense, Scosche Rhythm24 or Oura ring.
Main thing is to pick a method that’s convenient and affordable for you.
How do I measure my HRV
When testing your HRV you need to go with morning or night measurements, as they are the only two well established and reliable ways to measure your HRV.
Night time measurements
Night measurement: you wear a device (chest strap) each night, this device measures your HRV while sleeping, typically for a few minutes at a time, then the average of these time segments of measurement are used to calculate your HRV score. You must note that your data can be affected by the sleep stage it’s taken in, overall sleeping pattern that night and late evening/nigh training will affect your score as it takes time for heart rate to recovery fulling from training.
Morning measurements
Morning measurement: wake up, grab your phone, measure your HRV via phone camera, or chest strap. Your morning measurement typical will last from 1 and 2 minutes (longer is possible but not always necessary) this will then give you a HRV score.
What I use to test my HRV
I would personal recommend going with the morning measurements. It’s that bit more convenient and you don’t have to worry about how your training times will affect it. I would highly recommend using HRV4Training as I use this app myself and with our athletes. I find using the app the easiest way to test HRV purely down to convenience.
Getting the measurement right
The aim is to always measure your HRV with your body in the same position, typical I go for and recommend lying down while you’re in bed, easiest for most people typically. The main thing to remember you must take your measurement the same way each morning, so keep it simple. Measuring your HRV 3 times a week or less may be insufficient, while measuring 4-5 times a week can get you a good baseline, however the optimal way is to test and track each day and every day.
Using HRV to maximise your Recovery
HRV requires a certain amount of data to be accumulated before it can be computed. Therefore, you need serval days to define a base line in which your HRV score is calculated off.
What do you get?
In short, most apps will give you a score based on a 1-10 scale, the higher the number the better as this means you at a more rested state. On the flip side the lower the score means you are not as well rested in a higher state of stress.
- High HRV – higher parasympathetic activity, less stressed, ready to perform.
- Low HRV – inhibited parasympathetic activity, more stressed, tiredness.
Acute changes
An acute stress / stressor are experiences that can have an immediate effect on your physiology or can have an effect in the immediate future, lasting anywhere form 24-48 hours i.e. elevated heart rate, disrupted sleep. Acute stressors such as an intense training session can lower HRV. Hence a reduced HRV score can be used to determine if recovery or time off the next day is need. This level of detail is great in the short term (day to day) in order to make the necessary changes to your training intensities.
Long term changes
When it comes to trends you need to be looking at medium-long term trends with respect to your historical data. Comparing your daily HRV score to your historical data (baseline) is the easiest way to compare your current HRV to determine if there is a significant difference from what is your typical HRV for you is (i.e. lower score , indicating higher stress) with this information you can identify chronic stress patterns i.e. your training schedule, work stress etc.
HRV is a great tool to allow you to assess acute stress (day to day) & long term chronic stress (weeks, months) and with this info you have the power to make the necessary adjustments.
I hope you enjoyed todays read, don't forget to check out part 2 - 6 ways to improve your HRV.And please do remember that I’m here to help you in any way I can so don’t be shy and get in touch with any of your questions, Id be more than happy to help you.
Don’t forget to download our E-book on HRV for more practical tips on how you can take control of your recovery today's allowing you to train hard and most important improve your performance.
Here are the main areas that I cover in this eBook that can help you take control and push your performance to the next level.
- How to consistently track your HRV so you can trust the numbers.
- 2 most curcial ways to tweak your nutrition to maximise your adaption form your training.
- How to read into the long term changes to make the right adjustments with your training to keep you progressing through the year.
- Top 3 ways to mange your mental stress
References
- Burma, J., Copeland, P., Macaulay, A., Khatra, O. and Smirl, J., 2020. Effects of high-intensity intervals and moderate-intensity exercise on baroreceptor sensitivity and heart rate variability during recovery. Applied Physiology, Nutrition, and Metabolism,.
- 2020. Quickstart Guide. [online] Available at: <https://www.hrv4training.com/quickstart-guide.html> [Accessed 19 August 2020].
- James, D., Munson, S., Maldonado-Martin, S. and De Ste Croix, M., 2012. Heart Rate Variability. Research Quarterly for Exercise and Sport, 83(4), pp.533-539.
- Javaloyes, A., Sarabia, J., Lamberts, R., Plews, D. and Moya-Ramon, M., 2020. Training Prescription Guided by Heart Rate Variability Vs. Block Periodization in Well-Trained Cyclists. Journal of Strength and Conditioning Research, 34(6), pp.1511-1518.
- Kaikkonen, P., Rusko, H. and Martinmäki, K., 2007. Post-exercise heart rate variability of endurance athletes after different high-intensity exercise interventions. Scandinavian Journal of Medicine & Science in Sports, 18(4), pp.511-519.
- Michael, S., Graham, K. and Davis, G., 2017. Cardiac Autonomic Responses during Exercise and Post-exercise Recovery Using Heart Rate Variability and Systolic Time Intervals—A Review. Frontiers in Physiology, 8.
