Run, Ryan Phillippe, Run!

Looks like Ryan Phillippe has jumped on the latest celebrity bandwagon and embraced the whole topless craze.

The Stop-Loss actor and former Reese Witherspoon beau used the Hollywood Hills as his gymnasium yesterday, working up a sweat while running up and down the stairs.

His physical-fitness regimen appears to be yielding tremendous results. His girlfriend, Stop-Loss co-star Abbie Cornish, is probably so appreciative

that she doesn’t even mind washing those sweat-soaked trunks after his workouts.

In image-obsessed Hollywood, the pressure to stay fit is tremendous. If Ryan ever hopes to join the ranks of show biz’s greatest physiques, he’d best keep running those stairs.

For more sweat-inducing photos of a shirtless Ryan Phillippe, visit Pacific Coast News Online.