It always amazes me that FITNESS is a multi-billion dollar industry... Yet a solid, universal and concise definition of fitness is hard to nail down.
Just ask somebody taking part in a physical exercise routine, or even someone in the fitness market for that matter, to provide you with an obvious meaning of health.
You'll most probably be welcomed with the "deer caught in the headlights" gaze accompanied by nonsensical stammering.
If you do get a solution, it will most probably be slanted toward the specific abilities of the individual asked.
For example...

A marathon runner will define fitness in conditions of muscular and cardiorespiratory endurance... A power-lifter will define fitness in terms of absolute strength... A bodybuilder is going to define fitness in terms of muscle size as well as definition... etc.
But the overwhelming majority of people taking part in a physical fitness program are not professional athletes worried about the improvement of just one physical ability.
So, basing the definition of yours of fitness on one specific physical ability doesn't result in a universal definition of health colon broom and ibs (visit the following internet site) fitness.