As I studied what CrossFit was saying about fitness (work capacity across broad time and modal domains) and saw how my fitness could be defined as "the area under the curve" in a graph with power on the y-axis and duration on the x-axis, it was further posited that my health could be defined as "the volume under the curve" in the same graph with age on the z-axis.
I wondered why power is defines fitness and health?
Light bulbs are fit for our purposes according to a particular wattage and if a bulb were more complex and could lose wattage over time before it lost all function, power would make intuitive sense.
It is an estimation. How do I know my cholesterol is high? Compared to last time, it changed. How do I know it is high if I never tested before? Compared to someone else. But everyone is different. The "compared to everyone else" provides a range of relatively consistent variables. To become more accurate to me, they need the "compared to last time" measurement. Then they ask other questions.
Work: the ability to apply force for a distance demonstrates strength (ability to produce force) and stamina (ability to utilize energy) and endurance (breathing and circulation) among other things.
Capacity: how much work? That is power. How do we measure power? Easy! Work / Time. Of course, because we don't know how much work unless we know how long it took. Someone does three jobs in an hour and someone else does only one of those jobs in an hour or the same three jobs in three hours. While the three-jobs/hour work was the same as the one-job/three-hours work, the power output was greater in the first one, because we compare the same time unit with the amount of work produced. This is power output. It determines how long someone may keep their job. It also lets us know much work we are able to do when running or swimming or jumping or whatever activity we are doing.
They say healthier people are productive but that is like saying oranges are orange. Productive is healthy. In terms of a work environment in a market economy where goods and services reign supreme, there is a lot of repetitive work. Sounds like speed is needed and stamina is needed, right? When training for higher power output, the body adapts to be able to handle the higher power output. If there is lower power output to handle for a longer time, it is able to do that as well. The inverse is not true. Training for lower power output to handle for a longer time won't adapt for higher power output. This is "Why Power?"
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