Introduction: The Royal Netherlands Army, in collaboration with partners, is developing an integrated multi-sensor system to measure physical workload, performance, and health status of soldiers. This so-called Ambulant Registration of Military Operational Readiness (ARMOR) system can be used to measure or estimate gait speed, distance, step frequency, activity class, heart rate, energy expenditure, sleep duration, and core temperature. An innovative feature of ARMOR is the automatic assessment of load carried by soldiers by means of an instrumented insole in the military boot. The aim of the present study is to develop algorithms to convert raw insole output to carried load and to establish the validity of the load measurement.