title: The eMouveRecherche application competes with research devices to evaluate energy expenditure, physical activity and still time in free-living conditions.
abstract: The proliferation of smartphones is creating new opportunities to monitor and interact with human subjects in free-living conditions since smartphones are familiar to large segments of the population and facilitate data collection, transmission and analysis. From accelerometry data collected by smartphones, the present work aims to estimate time spent in different activity categories and the energy expenditure in free-living conditions. Our research encompasses the definition of an energy-saving function (PredEE) considering four physical categories of activities (still, light, moderate and vigorous), their duration and metabolic cost (MET). To create an efficient discrimination function, the method consists of classifying accelerometry-transformed signals into categories and of associating each category with corresponding Metabolic Equivalent Tasks. The performance of the PredEEfunction was compared with two previously published functions (f(η,d)aedes,f(η,d)nrjsi), and with two dedicated sensors (Armband® and Actiheart®) in free-living conditions over a 12-h monitoring period using 30 volunteers. Compared to the two previous functions, PredEEwas the only one able to provide estimations of time spent in each activity category. In relative value, all the activity categories were evaluated similarly to those given by Armband®. Compared to Actiheart®, the function underestimated still activities by 10.1% and overestimated light- and moderate-intensity activities by 7.9% and 4.2%, respectively. The total energy expenditure error produced by PredEEcompared to Armband® was lower than those given by the two previous functions (5.7% vs. 14.1% and 17.0%). PredEEprovides the user with an accurate physical activity feedback which should help self-monitoring in free-living conditions.
authors.affiliation: INRA, Unité de Nutrition Humaine UMR 1019, 63009 Clermont-Ferrand, France. Electronic address: romain.guidoux@ipleanware.com.
authors.forename: Romain
authors.initials: R
authors.lastname: Guidoux
authors.affiliation: INRA, Unité de Nutrition Humaine UMR 1019, 63009 Clermont-Ferrand, France; CHU Clermont Ferrand, Serv Med Sport & Explorat Fonct, 63003 Clermont Ferrand, France. Electronic address: mduclos@chu-clermontferrand.fr.
authors.forename: Martine
authors.initials: M
authors.lastname: Duclos
authors.affiliation: Laboratoire d'Informatique (LIMOS, UMR CNRS 6158), Campus des Cézeaux, 63177 Aubière Cedex, France. Electronic address: gyf@sfr.fr.
authors.forename: Gérard
authors.initials: G
authors.lastname: Fleury
authors.affiliation: Laboratoire d'Informatique (LIMOS, UMR CNRS 6158), Campus des Cézeaux, 63177 Aubière Cedex, France. Electronic address: placomme@isima.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Lacomme
authors.affiliation: Laboratoire d'Informatique (LIMOS, UMR CNRS 6158), Campus des Cézeaux, 63177 Aubière Cedex, France. Electronic address: nlamaudiere@cmcs-sport.fr.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Lamaudière
authors.affiliation: Almerys, 46 rue du Ressort, 63967 Clermont-Ferrand Cedex 9, France; Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM EA 7424), Université de Lyon, France. Electronic address: damien.saboul@almerys.com.
authors.forename: Damien
authors.initials: D
authors.lastname: Saboul
authors.affiliation: Laboratoire d'Informatique (LIMOS, UMR CNRS 6158), Campus des Cézeaux, 63177 Aubière Cedex, France. Electronic address: ren@isima.fr.
authors.forename: Libo
authors.initials: L
authors.lastname: Ren
authors.affiliation: INRA, Unité de Nutrition Humaine UMR 1019, 63009 Clermont-Ferrand, France. Electronic address: rousset@clermont.inra.fr.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Rousset
mesh_terms: D061725:Accelerometry; D003625:Data Collection / Q000379:methods; D004734:Energy Metabolism; D015444:Exercise; D006801:Humans; D008991:Monitoring, Physiologic; D009043:Motor Activity; D000068997:Smartphone; D012924:Social Conditions
keywords: Energy expenditure; Free-living conditions; Normal-weight adult; Physical activity intensity category; Smartphone accelerometer