[header] How to do an in flight fitness workout [title] Sit in your seat with your feet flat, hip-width apart and directly underneath your knees. [step] Lift your heels up so that only the balls of your feet are on the floor. Hold this position for five seconds and then lower your heels. 
Repeat this movement 10 times, making sure that your breathing is natural and at a regular pace. [title] Lift the balls of your feet so that only your heels are on the floor.