title: A stepwise validation of a wearable system for estimating energy expenditure in field-based research.
abstract: Regular physical activity (PA) is an important contributor to a healthy lifestyle. Currently, standard sensor-based methods to assess PA in field-based research rely on a single accelerometer mounted near the body's center of mass. This paper introduces a wearable system that estimates energy expenditure (EE) based on seven recognized activity types. The system was developed with data from 32 healthy subjects and consists of a chest mounted heart rate belt and two accelerometers attached to a thigh and dominant upper arm. The system was validated with 12 other subjects under restricted lab conditions and simulated free-living conditions against indirect calorimetry, as well as in subjects' habitual environments for 2 weeks against the doubly labeled water method. Our stepwise validation methodology gradually trades reference information from the lab against realistic data from the field. The average accuracy for EE estimation was 88% for restricted lab conditions, 55% for simulated free-living conditions and 87% and 91% for the estimation of average daily EE over the period of 1 and 2 weeks.
authors: Performance Branch, Swiss Federal Institute of Sport Magglingen, Hauptstrasse 247, 2532 Magglingen, Switzerland. martin.rumo@baspo.admin.ch
authors: Martin
authors: M
authors: Rumo
authors: Oliver
authors: O
authors: Amft
authors: Gerhard
authors: G
authors: Tröster
authors: Urs
authors: U
authors: Mäder
mesh_terms: D000054:Acceleration; D000328:Adult; D035843:Biomedical Research; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009043:Motor Activity / Q000502:physiology; D010827:Physiology / Q000295:instrumentation* / Q000379:methods*; D012044:Regression Analysis; D015203:Reproducibility of Results; D013997:Time Factors; D055815:Young Adult