ObjectivesThe Canadian Army fitness objective is FORCE COMBAT™. This consists of a 5km march (35kg) between 50–60min, and the annual FORCE physical employment standard as a circuit without the usual 5min rest intervals (FORCE circuit) in full fighting order (25kg). The objective of this research was to determine the number of practice attempts required to establish reliability of FORCE COMBAT™. Additionally, this study aims to identify the minimal detectable change once reliability is established. DesignThe study used a within participant design. Methods33 Canadian Army members were divided into two groups. Group 1 performed four maximum effort attempts of FORCE COMBAT™ completely. Group 2 performed only the FORCE circuit component, not the loaded march. On the fifth trial, the tasks of the groups were switched. Variability within and between trials of the FORCE circuit of FORCE COMBAT™ were analysed based on six statistical factors of reliability. ResultsFour statistical factors indicated that one maximal effort practice attempt of FORCE COMBAT™ is required, as reflected in the variability of performance between trials 1 and 2. The minimum detectable change, highlighting inherent measurement error of the test was 89.18s with 95% confidence. ConclusionsResults suggest that Canadian Army members should complete one FORCE COMBAT™ in completion at maximal effort, before formal assessment. Further, members performing within 89s of the recommended completion time, on FORCE COMBAT™ should be offered a re-attempt (in its entirety).