strenuous

Requiring great effort, energy, or exertion.

Vigorously active; energetic or zealous.

Strong; vigorous; active; pushing.

Eagerly pressing or urgent; energetic; zealous; ardent; bold; earnest; valiant; intrepid.

Necessitating vigor or energy; accompanied by labor or exertion.

Synonyms and Energetic, resolute.

Eagerly pressing or urgent; zealous; ardent; earnest; bold; valiant; intrepid.

Urgent, ardent, zealous.

Requiring great exertion.

taxing to the utmost; testing powers of endurance