Big Brother's Josie Gibson is more of a little sister now! She's dropped 5 dress sizes and 3 stone using 30-Second Slim. Personal trainer James Stark created this 'Short Sharp Slim' workout based on the latest science of 'High Intensity Interval Training'. It's 30 seconds of sweat, followed by an active rest. Three 20-minute workouts build in intensity from Level 1 - 3. In each there's… - Warm-Up: 4 minutes of easy calorie-burning moves. - Main Workout: 12 minutes of fat-burning intervals and moves to tone up the bum, arms and belly. - Cool Down: 4 minutes of stretches to lengthen the muscles.