What are some good metrics of physical health that indicate optimal mental productivity?

Question

Regular exercise and sleep all contribute mightily to productivity. With that in mind, I can think of the following physical health metrics for someone's productivy

1. Resting Heart Rate (lower is better)
2. # of hours sleep per night (higher is better)
3. Blood Pressure (lower is better)
4. Body fat percentage (lower is better)

What other physical health metrics would be good indicators of mental productivity?

Answer 1

The link between physical and mental health is very complex, and I don't think it can be broken down to a few variables. One thing I'd like to remark, though, is that cardiac function is very important for mental productivity.

Cardiac function is not best assessed by resting heart rate, but by measures such as stroke volume and ejection fraction. Only a cardiologist can make accurate assessments of these parameters. You can get a feel though by measuring how fast your heart rate rises in response to trivial challenges such as getting out of bed or walking to the kitchen. If you have a weak heart, your heart rate will rise steeply; if you have a strong heart, it will not. The strength of your heart has great consequences to your autonomic nervous systems and your stress response system, and therefore your productivity.

High-intensity interval training is a particularly good way to boost your cardiac function. Low-intensity or moderate-intensity exercise (cardio) are less effective.

Answer 2

None of the metrics you chose are simple:

• Resting Heart Rate (lower is better)

Some evidence shows that this is not the case. Too low often indicates a low resting metabolism. This can be fine for a sportsman who ramps up the heart rate when exercising, but for an office worker, for example, there may not be the physical load to ramp up, leaving them lethargic/slow.

• Number of hours sleep per night (higher is better)

I am much more productive with 4 or 6 hours sleep than either less than 4 or more than 7. Just the way my body clock works - you'd need to work this out for each individual.

• Blood Pressure (lower is better)

Not necessarily - I have a colleague who has problems in this area. Blood pressure low enough that if she stands up too fast she sometimes faints. There is an optimum middle ground, which varies by individual.

• Body fat percentage (lower is better)

Again - this is variable. Some individuals are better suited to a higher level of body fat than others.

tl;dr The core message I have is: it's all variable. You'd need to define metrics per individual and circumstance.