Glen Powell's got a treat for ya ... some clothing-optional shots that provide more than a glimpse of what Sydney Sweeney had to work with while they filmed down under. Poor girl, right?!?

Armed with a wide-brimmed hat to keep things PG-13, the "Top Gun: Maverick" actor bares his ass in a scorching-hot photo shoot for "Men's Health" magazine.

Some of the mag's other sexy snaps showcase his fine-tuned abs while jumping rope, trampolining and doing dumbbell push-ups.

Yup, it's just about fitness -- that's the ONLY reason anyone's looking at these pics.