You’ve got your workout planned. Only something feels different. Usually you can’t wait to attack your reps and dominate your sets. But today it’s as if your body is trying to tell you something.
When it comes to workouts, any one of a number of factors can affect how ready your body is to perform. Perhaps you went too hard the day before, or maybe you’ve been busy at work. It may be down to stress at work, or even just a late night followed by an early start.
It may feel as if your body is trying to tell you something. But it isn’t always easy to know what that something is.
Wouldn’t it be ideal if there was a simple measurement that could sum up exactly how prepared your body is to work out?
Step forward Heart Rate Variability (HRV): our favourite objective measurement of fitness and a great marker for determining general health, stress and recovery.
Heart Rate Variability
HRV measures the variation in time between your heartbeats, which is usually anything from below 20 to over 200 milliseconds. The exact figures are highly individualised and constantly changing, which means that what is considered to be a healthy HRV figure differs between people. When measuring HRV, it is therefore best to compare your results over time and assess your own HRV trends, rather than benchmarking them against someone else’s.
But what do those measurements mean? Well, HRV tells you how your body is balancing the two branches of your autonomic nervous system: sympathetic (increased alertness to activate the ‘fight or flight’ response) and parasympathetic (decreased alertness to return the body to a state of calm). Both of these branches constantly send input to the brain, and when they are balanced the body is perfectly prepared to adapt to its environment: whether that’s running from a bear or lifting a weight. This balance causes fluctuations in heart rate, which then gives a higher HRV score. The higher your HRV score, then, the more balanced these two systems are and the better prepared the body is for exercise.
HRV figures change with factors such as recovery levels, stress, emotions, environment and behaviour. If your figures are lower than normal then it means that one of these factors could be having a big impact on your body. Your nervous system will either be either stressed or fatigued and your body will be suffering, which means it could well be time for a rest.
Understanding HRV and monitoring it regularly is therefore an excellent way to know how your body is feeling, how to respond to stress and how hard to train – if at all.