Very interesting discussion with a lot to think about.

I'd just like to make one caution which is do not try to use absolute values of HR to measure anything. A more reliable measure is % of max HR. There is much more variability in maximum HR between healthy individuals than the commonly quoted (and discounted in peer reviewed articles) formulas suggest. I'm a healthy fit 57 yr old male who exercises regularly with a max HR of over 200, with a similar aged friend who has a max HR under 170. Interestingly both of us have resting heart rates around 60.

I'd be very interested to see a reference to the source of the HR ranges published above, not that a problem with the value of the given ranges matters to the underlying thesis which is well worth exploring.

On Monday, March 5, 2018 at 6:04:58 AM UTC+10, son_of_flubber wrote:
On Saturday, March 3, 2018 at 6:30:09 AM UTC-5, soarin wrote:

With a heart rate elevated to 115-145 BPM,
complex motor skills, visual reaction times and cognitive reaction times
are at their peak. However, between 145-175 mental and physical
performance begins to suffer dramatically.

I've no problem with the general idea, but since the author suggests the use of a heart rate monitor to measure stress level in the cockpit, I question the applicability of these specific numbers to pilots of different ages and fitness levels.

Talking averages... A 70 year old pilot would have a maximum heart rate of 220 - 70 = 150 bpm. I'd guess that he would experience debilitating stress well below 145 bpm. A 20 year old pilot would have a maximum heart rate of 220 - 20 = 200 bpm.

I'm not trying to say anything authoritative. I'm just questioning the numbers presented.

Source for calculation of maximum heart rate:

https://www.mayoclinic.org/healthy-l...-20046887?pg=2

"to calculate your maximum heart rate is to subtract your age from 220. For example, if you're 45 years old, subtract 45 from 220 to get a maximum heart rate of 175."