Actigraph Accelerometer Validation Study

Background: * Good measures of physical activity are needed for studies correlating physical activity and the risk of developing certain diseases. * In preparation for use in a study of diseases and risk factors in Hispanic populations, NCI is evaluating a new model accelerometer to measure physical activity. An accelerometer is a small device worn on a belt at the waist that measures and records movement, capturing movement intensity and duration and associating it with clock-time. * The new accelerometer (ActiGraph GTIM) uses a different type of motion detector from that used in the previous model (ActiGraph 7164). Objective: To evaluate and compare the ActiGraph GTIM with the ActiGraph 7164 by collecting physical activity data using both models. Eligibility: Men and women 18-74 years of age. Design: Study participants wear both model accelerometers while they walk or jog around a track at several self-selected paces. Data from the two devices are compared.