Gilgen-Ammann, RahelRahelGilgen-AmmannRoos, LilianLilianRoosWyss, ThomasThomasWyssVeenstra, Bertil JBertil JVeenstraDelves, Simon KSimon KDelvesBeeler, NadjaNadjaBeelerBuller, Mark JMark JBullerFriedl, Karl EKarl EFriedl2024-11-192024-11-1920211361-657910.24451/arbor.16833https://doi.org/10.24451/arbor.1683310.1088/1361-6579/ac19f9https://arbor.bfh.ch/handle/arbor/43031Objectives.; To investigate the validity of different devices and algorithms used in military organizations worldwide to assess physical activity energy expenditure (PAEE) and heart rate (HR) among soldiers.; Design.; Device validation study.; Methods; . Twenty-three male participants serving their mandatory military service accomplished, firstly, nine different military specific activities indoors, and secondly, a normal military routine outdoors. Participants wore simultaneously an ActiHeart, Everion, MetaMax 3B, Garmin Fenix 3, Hidalgo EQ02, and PADIS 2.0 system. The PAEE and HR data of each system were compared to the criterion measures MetaMax 3B and Hidalgo EQ02, respectively.; Results; . Overall, the recorded systematic errors in PAEE estimation ranged from 0.1 (±1.8) kcal.min; -1; to -1.7 (±1.8) kcal.min; -1; for the systems PADIS 2.0 and Hidalgo EQ02 running the Royal Dutch Army algorithm, respectively, and in the HR assessment ranged from -0.1 (±2.1) b.min; -1; to 0.8 (±3.0) b.min; -1; for the PADIS 2.0 and ActiHeart systems, respectively. The mean absolute percentage error (MAPE) in PAEE estimation ranged from 29.9% to 75.1%, with only the Everion system showing an overall MAPEenfitness trackersmilitary personnelphysiological monitoringwearable electronic devicesarticle