Marked by vigorous physical exertion
Possessing, exerting, or displaying energy
Strenuous fighting thereupon ceased.
Her lean body handled the strenuous task easily.
He was a strenuous advocate of reform, especially in the teaching of sciences, and supported the claims of modern languages to a place in the curriculum.
Frequently half his nights were spent in reading, after the labour of his most strenuous days.
The landing was effected in the face of strenuous opposition, Wolfe leading the foremost troops.