The 33-year-old star was photographed flashing his toned torso in a navy T-shirt after his workout session, reported AceShowbiz.
It looked like Hill dropped a large amount of weight when he was seen making his way through a parking lot in the T-shirt that he paired with black basketball shorts.
The "War Dogs" actor sported a scruffy beard and slicked back locks while carrying a bottle of water.
Hill has been working on getting in better shape after gaining weight for his role as former arms dealer Efraim Diveroli in last year's "War Dogs", in which he starred alongside Miles Teller.