Molly Sims and fitness guru Gunnar Peterson don’t mind when their pets shed — a few pounds, that is! The super model, 34, and her trainer have launched the PetFit Challenge to get people and their pups to lose weight. “It’s a neat way for you and your dog to get in shape,” Molly tells Life & Style. “It’s also a good bonding experience.”

Molly says she does exercises, including the Fetch Tease for Abs, with her Yorkshire terriers, Chloe and Poepette. “They love it. I pick up a ball next to me, and as I do a sit-up, they try to grab it. Then I come up and throw it and keep doing that.” Adds Peterson, “This puts a new twist on standard things you do when you’re with your pet. You do pet races, build a dog-stacle course and do lunges together. You mix it up.”

“We pretty much play and run every day,” Molly tells Life & Style.