Exertion

(n.) 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.

Thesaurus Entries

action, active use, activity, appliance, application, assiduity, assiduousness, consumption, determination, diligence, drive, effort, elbow grease, employ, employment, endeavor, exercise, exercising, good use, hard pull, hard usage, hard use, ill use, industry, misuse, operation, pains, push, resolution, rough usage, sedulity, sedulousness, strain, striving, struggle, toil, trouble, usage, use, using up, while, work, wrong use