Measurement of human daily physical activity.

OBJECTIVES To validate a new device, Intelligent Device for Energy Expenditure and Activity (IDEEA), for the measurement of duration, frequency, and intensity of various types of human physical activity (PA). RESEARCH METHODS AND PROCEDURES The ability of IDEEA to identify and quantify 32 types of PA, including the most common daily exercise and nonexercise PA, was tested in 76 subjects: Subjects included males (N = 33) and females (N = 43) ranging in age from 13 to 72 years with a mean body mass index (BMI) of 24.7 kg/m(2) (range: 18.4 to 41.0) [43 females: 13 to 72 years old and BMI 18.4 to approximately 41.0 kg/m(2) (mean = 24.7 kg/m(2)); 33 males: 15 to approximately 72 years old and BMI 21.0 to approximately 38.4 kg/m(2) (mean = 25.9 kg/m(2))]. Postures, limb movements, and jumping were tested using a timed protocol of specific activities. Walking and running were tested using a 60-meter track, on which subjects walked and ran at 6 self-selected speeds. Stair climbing and descending were tested by timing subjects who climbed and descended a flight of stairs at two different speeds. RESULTS Correct identification rates averaged 98.9% for posture and limb movement type and 98.5% for gait type. Pooled correlation between predicted and actual speeds of walking and running was high (r = 0.986, p <or= 0.0001). DISCUSSION IDEEA accurately measured duration, frequency, type, and intensity of a variety of daily PAs.