Treadmill - 10% incline @ 3 mph

This activity burns approximately 480 calories per hour

If you enjoy walking and want to challenge yourself without having to run, try walking on a treadmill and slowly increasing the grade. After a brief warm-up, begin walking at a 5% inclination and increase the grade 2% every 5 minutes until you've reached a 10% incline. Maintain this speed for at least 20 minutes, and then cool down for another 5 minutes.