Hilaria Baldwin Gives Workout Tutorial In Skimpy Bra & Undies, Watch Video

Hilaria Baldwin wasn’t about to gatekeep her gym-honed bod -- she tossed out a few fitness tips while rocking the tiniest workout set ever ... just in case her fans needed a little visual motivation.

Check it out ... Alec Baldwin stays winning, 'cause Hilaria hit the floor in a baby-pink sports bra and red undies to demo proper form for legs, butt, abs, and lower back ... though LBH, nobody was tuned in for the tutorial.

Hilaria dialed the sexy all the way up ... kneeling on a plush bedroom carpet and arching back, all to give those washboard abs their moment.

After dropping her workout wisdom, she seductively crawled toward the camera to turn it off -- serving one last eye-popping view in the process. Alec clearly approved ... hitting the clip with a big ol' like.