The Collaborative International Dictionary
effortful \effortful\ adj. 1. requiring great physical effort. Opposite of effortless. [Narrower terms: arduous, backbreaking, back-breaking, grueling, gruelling, hard, heavy, laborious, labourious, punishing, slavish, strenuous, toilsome; exhausting, tiring, wearing, wearying] Also See: difficult, hard.
Wiktionary
a. Requiring or showing effort.
WordNet
adj. requiring great physical effort [ant: effortless]
Usage examples of "effortful".
First she had produced a tremendously effortful Thai banquet flavored with Nam Poc and lemongrass which she had gone out of her way to procure some where, and then she had created an ambitious coulibiac of salmon so substantial she had to convey it to the table on the dusted-off Thanksgiving turkey platter with branches of parsley obscuring the holiday motif.
He is indeed rather tubby now, the back resting burdensomely on the buttocks, and he walks with an effortful, cross-footed gait.
The camera Had moved in for a closeup, the white teeth, tremolo of tongue, effortful throat, vast enunciations of the lips.