What is the Definition of Fitness?

The princeton.edu definition for fitness is – the quality of being suitable. Suitable for what? For life? For bodybuilding? For powerlifting? For a particular job? For what? Princeton.edu provides a sample sentence: “They had to prove their fitness for the position.”

Interesting. I actually like this definition of fitness. I once made a short video where I stated something like, “Fitness has nothing to do with losing weight or gaining muscle. It has to do with being healthy.”

A Practical Example

A bodybuilder friend of mine responded by saying, “You’re contradicting yourself.” Lets do a little experiment in word replacement:

What I’m saying is, “Being fit means that you are healthy.”

Apparently, according to my bodybuilder friend, fitness means the same as:

“Having a six pack means you are healthy.”


“Having big biceps means you are healthy.”


“Being able to run 24 miles in a few hours means you are healthy.”

Here are my thoughts:

  • A six pack does not necessarily mean that you are healthy, because you could have gone through some extreme form of dieting that could be potentially harmful to your body. In this case you look healthy, but may not be much healthy once you get your blood work done.
  • Same goes for the guy with big biceps. How many guys are walking around with huge arms and inflated chest, along with a belly hanging down to the ground? They’re just strong, but don’t look very fit. They wouldn’t be able to run very fast, nor would they be able to lift their own bodyweight for high reps.
  • Finally, lets take the last example. Most distance runners are extremely skinny. They lack fundamental levels of strength and some even look sick- borderline anorexic. I would not call them healthy.

So then, what exactly is the definition of fitness? I would love to hear your thoughts.