 The purpose of this study is to determine and link cadence the number of steps taken in a minute to the intensity of physical activity e.g. low-, moderate- and vigorous-intensity in adults 21-85 years old. The investigators anticipate that cadence will be a good indicator of exercise intensity. Identifying how cadence relates to activity intensity will allow for physical activity guidelines to be communicated to the public in a manner that is more accessible to the lay person. 