If you want to track your overall health and performance, and in particular avoid over-training, what should you measure? What device should you buy to give you insight into when you should push harder, and when you should really just rest up.

Over the years I have tried tracking a number of metrics. Heart Rate Variability (HRV) is a popular metric, that is supposed to give you a good overall picture of your readiness to train. I have also tracked CNS score, reaction times, resting heart rate, weight, sleep quantity and quality.

After tracking HRV with a dedicated OmegaWave device, and other heart rate monitors such as the Polar H7 in conjunction with various apps, I am yet to be convinced the results are consistent with my ability to perform.

I think one of the  worst metrics is weight. If you are competing in a sport that you must fit into a weigh category, then it is obviously important, but as to your general health lighter is not always better.  It is easily affected by hydration levels and glycogen depletion.

I have been between 73 and 90 odd kilograms. When I was at 73 kilograms, I was thrashing my body with long arduous training sessions in excess of two hours, and restricting my calorie intake significantly. This lead to an extended period of 12 to 18 months to recovery from the over-trained state I had put myself in. This morning I’m 77.3 kilograms after six weeks of high fat, low carb diet with no calorie restriction and trying to keep additional training outside of Jiu-jitsu to high intensity, low duration to minimise the amount of recovery needed.

The two metrics that I see reflect the progress of my training are reaction times, and resting heart rate. As my Jiu-jitsu volume and intensity increases in preparation for competition, I see my reaction times generally trend downward. When you feel faster, it’s because you are faster.

For me, resting heart rate is the key metric that shows me the state of my recovery. When it starts going up, I start backing off. When it stays low, I know I’m good to keep pushing. I try to maintain the integrity of the measurement, by using an accurate measurement device, and having a consistent environment to take the measurement.