Treadmill - level @ 6 mph

This activity burns approximately 664 calories per hour

For most individuals, walking at 6 mph represents a slow run. At this pace, walking on a treadmill may actually be more efficient than breaking into a jog. If you can't sustain jogging at this pace, try jogging in intervals. Jog for 5 minutes, and then slow down to a walk for 5. Repeat the sequence.