A Ramp Protocol with Increasing Incline and Additional Weight for Special Operation Forces Provides a Valid Assessment of V.O2max

INTRODUCTION: Accurately measuring aerobic endurance in military and police Special Operations Forces (SOF) and in load-bearing sports requires a cardiopulmonary exercise test protocol that incorporates load and terrain demands. We developed a ramped treadmill test incorporating a 12.6 kg vest and incremental incline and evaluated its validity against a standard speed-ramped protocol. MATERIALS AND METHODS: Twenty-three healthy and trained volunteers completed both protocols in randomized order. Breath-by-breath V˙O2 and heart rate data at the ventilatory thresholds 1 and 2, as well as V˙O2max were compared using Bland-Altman plots, two one-sided tests (TOST), as well as Bayesian range of practical equivalence (ROPE) using ±2.84 ml/kg/min (V˙O2) and ±3.1% (HR) pre-defined boundaries for insignificant difference. RESULTS: Mean test duration was 710 ± 85 sec with both protocols. V˙O2max differed by -0.2 ml/kg/min (95% CI -1.3 to 0.9). TOST did not confirm strict equivalence, but Bayesian ROPE placed 100% of the posterior within ± 2.84 ml/kg/min. Submaximal V˙O2@VT2 and HR thresholds met 95% ROPE criteria; V˙O2@VT1 narrowly missed. CONCLUSIONS: A vest-loaded, incline-ramped CPET designed for SOF tasks and sports disciplines that involve carrying additional load produces practically equivalent values of V˙O2max compared to a traditional speed-ramped protocol. The new protocol allows for accurate V˙O2 and heart rate measures for SOF and athletes carrying weight on steep terrain, while also providing a task-specific experience.