Monitoring driver's heart rate is as vital as monitoring oil pressure or engine rpm.
The human heart reacts subconsciously to stress, fatigue, anxiety, dehydration, heat and many other factors. Monitoring a driver's heart rate will tell a story, and in many cases may show where a driver can improve their performance typically with minor modifications.
continually gathering more data and finding measurable results on performance. Identifying stress and keeping it below an individual's threshold has shown performance gains without touching the car.
Establishing a 'baseline' heart rate on a test day is a good start. We have seen a driver's heart rate increase in a particular section of a circuit or even just in one corner. This is a good indication that the driver is not as confident in that section, which could be something with the car or possibly a part of the circuit that have not mastered yet. On a race weekend you may notice large variations on heart rate, which can indicate stress, fatigue and even poor nutrition.
We continue to learn more every day, but what we can say for certain right now is that every driver should monitor their heart rate.