Varying your stride length uses more energy than walking at a steady pace, which may help you burn more calories.
Adam Grimitt Researchers at the University of Massachusetts Amherst recruited 18 adults between the ages of 18 and 45 and asked them to walk normally on a treadmill for five minutes while their average stride length was recorded with a motion capture system.
Building on this, the researchers then manipulated stride length during a further five minutes of walking by illuminating desired locations on the treadmill.
Source: www.newscientist.com