Jennifer Aniston: Smart Water Sexy

Man, Jennifer Aniston just looks so hot ... literally.

In a new ad campaign for SmartWater, the actress is drenched in sweat, showing Brad Pitt what he's missing ... her ripped, impressively toned abs.

Wearing workout gear and clutching a bottle of water, the physucally fit 41-year-old gives the camera a breathless look. The text of the ad reads:

"Working out feels great... afterwards ... That's why I drink Smart. It's hydration I can feel. (And that's one part of my routine I never sweat.)"

Enough talk. More hotness (and fitness) ...

Smart Water Hottie

Jennifer Aniston makes you want to reach for ... SmartWater.

Yoga and fitness buff Aniston, who some say has the best body ever, has been a brand spokeswoman for Glaceau SmartWater since back in 2007.

Hey, it's not Jennifer Aniston nude (like her new perfume ads) but it's pretty solid. Makes you want to ... work out? Maybe a little if she were there?