This is the second part of my interview with trainer to the stars Gunnar Peterson. He already dished about his celebrity clients, and now he's sharing tips on working out faster and smarter. Why spend an hour when you can get your workout done in half the time, right?

It's not just celebs who benefit from Gunnar's expertise. All of us are busy and want the most out of our workouts, and he has some great suggestions. Say you only have half an hour to spare. "Work the big muscle groups," he said, "and incorporate multi-joint exercises [like lunges with lateral raises or squat press and jumps, which work the upper and lower body]. Do cardio blast intervals in between." For example, if you're doing bench presses, go from that to working your abs with the bicycle movement, then do a series of squat jumps, followed by a quick sprint on the treadmill.

In terms of strength training, he occasionally has to do a little convincing with new female clients. "Big weights don't give you big muscles -- big food gives you big muscles," he explained, saying the belief that "big weights add bulk, light weights tone, and cardio burns fat was written by one guy living in a cave in the 1980s -- there's more to it than that." He bases the size of his clients' weights on where they are in their workout, not on whether they're male or female.

Gunnar shared a couple of secrets for looking great and working out harder. First is rest. "Even if you have to take that time away from the gym, you need to get your rest. Recovery is as much a part of training as training," he explained, which is something we all need to remember this time of year.

Second, he really stresses proper hydration. He's a current spokesperson for Gatorade, so I had expected that. What I hadn't expected was for him to say he'd been skeptical of the sports drink. "People are always worried about the sugar, and the calories, but the thing is, you get more bang for your buck -- you work harder, and you work better." And, he went on to say that by taking in a few calories during your workout, you will likely take in fewer post-workout, which was news to me.

After hearing all this, it's no wonder he keeps Hollywood's elite in top shape. To see Gunnar's TV appearances, read his magazine articles or just find out more about him, check out his website right here.