The female contestants from Survivor: The Australian Outback may look like they were plucked right from Hugh Hefner's Playboy manse (save for Mad Dog, natch), but for the latest chapter of the adventure race show, Eco-Challenge (debuting Sunday at 8 pm/ET on the USA Network), producer Mark Burnett did one better: He recruited actual Playmates.

Team Playboy X-treme — one of 76 co-ed teams competing in the 320-mile race — features former pin-ups Danelle Folta (Miss April 1995), Jennifer Lavoie (Miss August 1993) and Kalin Olson (Miss August 1997). Prior to Eco-Challenge, the trio have participated in a number of expedition races, and Burnett insists that's the primary reason he brought them on board. "They're very, very fit," he says. "They're real athletes. They aren't just jumping out of the cover — you couldn't do it. They're real extreme athletes... and they applied."

Still, Burnett — the brainchild behind Survivor — concedes that the addition of Team Playboy serves a higher purpose. "It kind of pisses me off that [these races are] always about testosterone and tough guys," he groans. "And I've learned through seven Eco-Challenges that women are far, far tougher than men. And it's mainly because the male... ego gets fully in the way in an expedition, and the males all want to dominate. I believed that women could do incredibly well, and I was right."

Eco-Challenge — which involves a host of physical trials, including rafting, swimming, biking and climbing — airs in five installments Sunday through Wednesday (the final two parts run back-to-back from 8 to 10 pm/ET Wednesday). The franchise moves to USA Network after four years on the Discovery Channel — a switch, Burnett claims, that led to a major revamp. "Discovery Channel is all about education," he explains. "USA Network is general entertainment, which allowed us to focus on telling the dramatic stories of six to eight teams, and their journeys from the start line through to the finish line."

And if one of those teams consists of three onetime Playmates, even better.