lacking energy in inglese:

Why have you decided to rely on that indolent guy?

He was an indolent man, who lived only to eat, drink, and play at cards.

Salon wrote: “Hilton is the one everyone has come to see, and her indolent, dull coolness does not disappoint.”

I feel listless and have a throbbing headache.

The heat made us all feel listless.

I feel lethargic.

Nothing can make a person more lethargic than a big turkey dinner.