Dilbert_X wrote:
Body fat is not a bad indication of body condition, but no indication of fitness, V02 max is better.
Big fat steroid muscles aren't a help there as its largely heart/lung capacity.
But the methods used to measure VO2 max outside of a lab environment are shit, as well. Too prone to error that have nothing to do with the body's ability to process oxygen. That's why the USAF finally got rid of that monstrosity of a bike ergometry test (supposed to measure VO2 max)--too easily swayed by heart rate spikes that had nothing to do with fitness levels (test anxiety, etc).
The best way to measure fitness is to identify tasks, apply standard criteria to them, and see if people can meet those criteria. BMI is not one of those, as it does not account for muscle mass vs fat mass. Nor does the standard abdominal circumference measurement, as it does not account for height (I shit you not--a guy who's 5'2" with a 36" waist is supposedly just as fit from an AC perspective as a guy who's 6'2" with the same waist measurement)--which is complete nonsense.
I've seen "fat slobs" with great VO2 max scores and skinny bastards with shit poor ones. It's all about whether they are actually putting in the time, doing the necessary exercise--not what they look like.