Like many endurance athletes – runners, cyclists and triathletes – I used a heart rate monitor. It helped me measure how hard my body was working during training as well as keeping me just to the right side of the red line during competition.

Since I wasn’t getting any younger and I liked to keep pace with the top local, and yes, younger riders, I began investigating smarter training methods that would improve my performance but without the risk of injury due to overtraining. This is how I found out about heart rate variability.

In time, I became convinced that I needed to incorporate HRV as part of my own athletic training. So I looked around to see what commercial products were available and came to the conclusion that there was not an easy-to-use, affordable product that could give a direct and daily measure of HRV together with visual aids to interpretation such as traffic light training indicators and trend charts. But all was not lost. As an engineer by profession, building an HRV system did not seem particularly daunting.