Most people engaged in competitive sports have experienced soundly beating an opponent with apparent ease, only to be crushed by the same foe on a later date. They are left wondering: what did I do differently?

According to Alan Watkins, a British medical doctor who also has degrees in psychology and immunology, it is all about the signals your heart is sending to your brain. Dr Watkins has developed a speciality in teaching athletes and business leaders about the science of heart rate coherence to help them achieve more consistent performance.

What is coherence? I’ve written before about heart rate variability, which reflects the fact that your heart beats at different rates over time. The interval between heartbeats is your HRV and measuring this can help you determine when your body is fully rested.