David Bassett’s primary research area is the measurement of physical activity and energy expenditure in humans, using objective methods. He and his colleagues study the validity and reliability of pedometers, activity monitors, and fitness trackers, with a particular focus on standardizing daily step counts. In some of these studies, direct observation of steps and a digital hand-tally device are used as the gold standard. In others, a GoPro camera mounted to a chest harness and pointed down at the feet, has allowed the quantification of steps in the free-living environment. Bassett and his co-workers conduct research on walking in various populations. They have collected data on groups ranging from school children to sedentary, middle-aged adults to Amish farmers. They are exploring the relationships of ambulatory physical activity to body weight, blood pressure, blood lipids, and other cardiovascular risk factors. A number of their studies have shown the benefits of walking for weight control, blood pressure, and glucose tolerance.