See strenuous in Webster's New World Roget's A-Z Thesaurus II
adjective
Marked by vigorous physical exertion:
knockabout, rough, rough-and-tumble, rugged, tough. See actionPossessing, exerting, or displaying energy:
active, brisk, dynamic, dynamical, energetic, forceful, kinetic, lively, sprightly, vigorous. (Informal) peppy. See action
Learn more about strenuous