Is there a definition of a workout?

What is a workout? JB defines a workout as:

Brief periods of self induced physical and mental anguish followed by a couple days of muscle soreness.

Well, that is definitely one way to define a workout. I think of a workout as an incremental step in building muscles, building strength, developing endurance, strengthening the heart, and expending calories. (I probably should add becoming more flexible and creating an ability to have balance. I don't work on those aspects too much for the exception of stretching after a workout).

A buddy of mine is exercising in functional ways--using an ax, toting limbs, clearing rubbish is his way of expending calories and building muscles.

When the workout causes the muscles to be sore, I know I have stretched the muscles so that they will tighten and strengthen. Let's admit it. After a leg workout or a run, the tightness in the legs feels great! Don't you think?

It really doesn't matter how you exercise or what your workout is. Expending calories and building endurance can happen almost at anytime. It does not have to be at gym or on the track. Stand instead of sit; walk instead of ride, jog instead of walk, run instead of jog. Do crunches on the couch while watching TV, dance with kids. Move, move move.