Treadmill - 15% incline @ 2 mph

This activity burns approximately 434 calories per hour

One of the best ways to challenge yourself is to add an incline to your treadmill workout. Begin by warming up at a 2-mph pace. While maintaining your walking speed, slowly raise the elevation 1 to 2% every 5 minutes until you reach a 15 % grade. To avoid injury, avoid increasing the elevation too quickly.