Kim Kardashian, It's a Miracle My Sports Bra Stayed On!!!

Kim Kardashian's sports bra was hanging on for dear life as she trudged up an L.A. canyon.

Kim and the girls went for a walk Thursday in Fryman Canyon near her Bel Air home. Her pal, Carla DiBello, and her personal trainer, Don-A-Matrix, were by her side, and their focus was broken just once ... to greet some adorable pooches.

As we reported, Kim and Kanye have made a deal with a surrogate for baby #3.