It always amazes me that FITNESS is a multi billion dollar industry... Yet an excellent, concise and universal definition of fitness is tough to nail down.
Just ask an individual taking part in a physical exercise - https://twitter.com/search?q=physical%20exercise&src=typd routine, and Keto diet pill - https://www.federalwaymirror.com/national-marketplace/regal-keto-review-... even someone in the fitness industry for that matter, to give you a clear meaning of health and fitness.
You will most likely be greeted with the "deer seen in the headlights" stare accompanied - http://Search.Un.org/search?ie=utf8&site=un_org&output=xml_no_dtd&client... by nonsensical stammering.
If you do get a solution, it'll most likely be slanted toward the specific proficiency of the person asked.
For example...
A marathon runner will define fitness in terms of muscular and cardiorespiratory endurance... A power-lifter is going to define fitness in terms of absolute strength... A bodybuilder is going to define fitness in conditions of muscle size as well as definition... etc.
But the overwhelming majority of people participating in a physical fitness program are not professional athletes concerned with the improvement of one physical ability.
So, basing the definition of yours of fitness on a single specific physical skill does not result in a universal definition of health.