The act of exerting, or putting into motion or action; the active exercise of any power or faculty; an effort, esp. a laborious or perceptible effort; as, an exertion of strength or power; an exertion of the limbs or of the mind; it is an exertion for him to move, to-day.
I have no faith in human perfectability. I think that human exertion will have no appreciable effect upon humanity. Man is now only more active - not more happy - nor more wise, than he was 6000 years ago. Edgar Allan Poe
Success depends in a very large measure upon individual initiative and exertion, and cannot be achieved except by a dint of hard work. Anna Pavlova
The half minute which we daily devote to the winding-up of our watches is an exertion of labour almost insensible; yet, by the aid of a few wheels, its effect is spread over the whole twenty-four hours. Charles Babbage