5 Celebs With The Easiest Workout Routines

Julia Roberts

The almost-50-year-old actress has the figure of a half-her age, yet her trainer's favorite workout doesn't include the gym. She does circuit and strength training with 5-pound weights.

Carrie Underwood

When she wants an easier exercise, Carrie Underwood uses Tabata. The exercises last four minutes: Choose one motion and perform it in 20-second bursts with 10-second breaks. The country artist mixes four-minute workouts.

Kristin Cavallari

Since becoming a mom, Cavallari has cut out long stints of cardio and instead relies on short circuits of weight training with moves she's picked up from former personal trainers

Sophia Bush

Sophia Bush like to burn calories without moving. Selena Gomez, Emmanuelle Chriqui, and others book "sweat sessions" at Shape House, the first and only urban sweat lodge.

Jessica Biel

When she wants to switch things up, Jessica Biel heads outside. Her favorite thing to do out there doesn't require circuits or any equipment. She just hikes through the hills of Hollywood.