Fleshbot has a write-up on Aria's Sexxx Training Camp, a video featuring porn stars working out (and also engaging in sex - duh!). There's a video clip embedded in the Fleshbot post, Flesh Flicks: Sexxx Training Camp. From the post:
This movie trailer depicts a magical fitness center where female athletes sculpt their body for competition, and where "competition" really means "fucking your personal trainer." Okay, it's not the most original conceit ever for a porn movie, but there's something about the topless overhead press that gets us going. If you don't plan on actually working out yourself today (and why would you?) stay on the couch and make this part of your regimen instead.
It should go without saying that the Fleshbot post, the video trailer and the film itself are all NSFW.
