In the age of of Apple watches and Fitbits, we’re more aware of our health stats than ever. We know how many steps we take each day, hour many hours of quality sleep we get, and exactly how many calories we eat and burn. It’s useful stuff to know because, to quote author Tim Ferris, “what gets measured gets managed”.

And management in fitness is key. Over my ten years in the industry I’ve seen so many people crash and burn because they don’t manage their effort. They train to oblivion, suffer with fatigue, and ultimately get sick and have to take time off. I’ve done it a few times myself. It’s poor management: you put work in, but get poor health back.

I’ve often wondered if there would ever be a machine that could tell you exactly how recovered you were and could help you decide whether to train or rest. To that end, I’d like to introduce you to heart rate variability tracking, a tool which is a huge step in that direction.

What is heart rate variability?

Heart rate variability is an indicator of how well our parasympathetic nervous system is working. It has been used for a long time in hospitals to treat heart patients and, relatively recently, has become known as a great biofeedback tool for athletes looking to improve their performance.

Without going into too much technical detail, heart rate variability is essentially the gap between heartbeats when you are resting. A longer gap between heartbeats indicates you are well rested, whereas a shorter gap could mean you are stressed out and running the risk of overtraining. This relatively simple measurement, in turn, provides athletes with a solid idea of a) how well they have recovered from previous exercise, and b) how well they can expect their upcoming workouts to go.

Before HRV became widely accessible most efforts at recovery were based on how we felt. That’s not always easy to work out. Ask yourself now: how do you feel? Then ask yourself: when did you last eat, how long have you been looking at a computer screen, and how much work do you have to get done today? You see how many variables effect your response?

The beauty of HRV is that it gives us an objective reading of recovery. If you err in favour of pushing too hard, you can’t hide it when your pulse is measured.

What are the health benefits?

It is not an exaggeration to say that heart rate variability is an extremely important indicator of our general health. There are many widespread health issues that have been linked to poor HRV, including obesity, diabetes, hypertension and other potentially life-threatening cardiovascular diseases. Also, high levels of stress for long periods of time can suppress the immune system, leading to a higher risk of illness and, in the worse case scenario, untimely death.

Comparatively, learning how to allow your body to recover and optimise your heart rhythm and breathing to create a consistent HRV has been strongly linked with physical and emotional benefits. These include reduced anxiety levels, reduced cortisol levels, decreases in high blood pressure, as well as mood improvements and improved physical stability.

For athletes, there seems to exist a close relationship between aerobic and anaerobic exercise and an increase in HRV. This suggests HRV is a good indicator of exercise performance and can be utilised to predict positive outcomes, such as enhanced physical ability, not just negative factors such as over-training and fatigue.

Who’s doing it?

It is now commonplace for elite athletes making regular who want to get the most from each and every training session, to start the day by taking a HRV measurement.

Bantamweight champion Miesha Tate is one of the famous faces who has used HRV to dictate her training and recovery schedule in the lead up to a big fight, with impressive results.

With increased accessibility to heart rate monitors and an explosion in mobile technology designed to allow us to measure HRV inexpensively in our homes, the method is only going to become more popular at all levels of athletic performance. As more and more people start to pay more attention to their health and wellbeing, fitness trackers like these, which help us to improve ourselves and lessen our stress simultaneously, will become a key way to gain an edge over our fellow competitors, as well as ourselves.

How can I apply it to my training?

It doesn’t matter if you are a competitive athlete or a weekend warrior; knowing your rate of recovery and stress level can be a huge advantage for predicting the success of future workouts, as well as the general condition of your nervous system.

There are loads of ways to monitor the health of our nervous system, from sleep analysis to looking at the function of nerve fibers. All of these methods work to a degree, yet HRV is rapidly becoming the preferred approach for many people, largely due to its accessibility, ease of use and general accuracy.

As far as training is concerned, measuring HRV over time allows us to take the guesswork out of the two main variables of productive exercise: intensity and recovery. It also gives us the power to tailor programs to fit the abilities of each person, with regards to mental and physical performance and resistance to injury and illness.