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 ∼41.0 kg/m 2 (mean = 24.7 kg/m 2 ); 33 males: 15 to ∼72 years old and BMI 21.0 to ∼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 ≤ 0.0001). Discussion: IDEEA accurately measured duration, frequency, type, and intensity of a variety of daily PAs.