* SPRINT! To boost calorie burn in your workouts, do high-intensity intervals on a treadmill or elliptical machine, says trainer Pat Murphy.

* CIRCUIT TRAIN Do four strength-training moves (think lunges and crunches) back-to-back to challenge the body, says trainer Teddy Bass.

* EAT BREAKFAST "It prevents you from impulse-eating later on," says Small Changes Big Results dietician Ellie Krieger. Try whole-grain cereal.

I'd diet two weeks and then be off it," the five-foot-two Laguna Beach alum, 19, tells Us. To kick her yo-yo habit and get lean, Cavallari eats small meals, snacks on almonds and lifts weights for an hour three times a week. "This is the first time I've actually stuck with a diet," she says.

"I have to give in every once in a while," Cavallari tells Us of her diet. "Otherwise, I'll binge." Her treat: carrot cake.
[US Weekly]