A guide to using HRV as a measure of readiness to train and improve recovery.
Why measure HRV?
Gain an important insight into how well your body is ready to perform.
HRV measurement is simply measuring the variation in time between heart beats, this is also known as R-R intervals, hence why a compatible HR monitor is needed. These intervals are affected by the autonomic nervous system (ANS). The ANS is made up of the parasympathetic nervous system (PNS) and the sympathetic nervous system (SNS), the latter being responsible for the fight or flight
response and the former responsible for the rest and digest
response in the body. Knowing the dominant nervous system day to day can give an indication as to how recovered (or not) your body is, allowing an insight into whether you are ready to perform (or not).
Without going back into my 3rd year physiology notes and completely losing you on this, when the body is resting we expect to see a higher variability in heart beats than to when the body is under stress. So, a higher HRV score shows the body to be in a more recovered state. How this is worked out is through a time based formula called rMSSD, which stands for the Root Mean Square of the Successive Differences. Yep, knew I'd lose you.
Understand how your body is really coping with training stress.
Over time, data can be logged and then reviewed to see how different sessions affect the ANS. Depending on sporting background, lifestyle, environment etc... different workouts will affect individuals in different ways. An endurance athlete may be significantly fatigued (PNS dominant) following a strength workout than say an experienced weight lifter. Even though they have done the same session it causes a dramatically different amount of stress on the body.
Prevent over training which can inhibit maximising performance.
Ideally training should stress the body enough to cause a drop in HRV, but there should also be adequate recovery time within the training program to allow the body to adapt. If HRV is consistently low, it could show a sign of over training which means adaptation and compensation to the training is not taking place as quickly as it should, or even at all.
So in practical terms, HRV helps you to know how stressful your current training and life actually is and how well your recovery techniques are working. Once you know this, things like sleep, diet and other external stressors can be addressed and monitored in order to teach your body to enable PNS dominance to enable greater recovery and stress relief.
How to measure HRV?
Tools of the HRV trade.
Wahoo TICKR Heart Rate Monitor for iPhone & Android
Polar H7 or H10 bluetooth heart rate monitor.
- HRV4 training app (available on the App Store and Google Play)
- Heart rate monitor capable of measuring and transmitting unalterred R-R intervals via bluetooth 4.0 or ANT+.
To eliminate as many affecting variables as possible on your individual heart rate variability take a short (2:30 min) reading each day. Ideally you want the reading to happen at the same time, in the same way.
The best method is to be horizontal in a relaxed manner, I recommend doing it before you get out of bed in the morning. Lye still during the reading and breathe in a normal relaxed manner.
Stresses of the day haven't had chance to affect you once you have just awoken. Your circadian rhythm and hormonal patterns should be consistent at that time as they were the previous day hence why it is important to be consistent with the time of day you record a reading.
HRV is highly based on individual circumstances. Everything from your mindset to air quality to age and exercise patterns can affect HRV.
Scoring low on any given day is usually nothing to worry about. It is your average over time that matters the most, hence why it is important to take readings regularly if not everyday.
Working towards improving your average HRV over time is an achievable goal through enhancing recovery techniques. Speak with Tom to learn more and have an individual plan set out for you. Remember the key to improvement is acute stress (training) followed by adequate recovery.
By: Tom Walker, Endurance Coach
Any further questions mail Tom on firstname.lastname@example.org