Assessment of Physiological Adaptation and Altitude Tolerance Among Military Recruits Deployed to High-Altitude Peacekeeping Operations from Nigeria

Background: Nigerian military personnel deployed to peacekeeping operations in highland regions of East and Central Africa face acute mountain sickness and physiological altitude stress. Baseline fitness, haematological indices, and acclimatisation capacity of Nigerian military recruits are poorly characterised, limiting pre-deployment health planning. Objectives: This study aims to compare haematological and cardiorespiratory physiological responses to simulated hypoxic exposure equivalent to 3,000 metres altitude between Nigeria Army recruits who have undergone structured pre-deployment physical conditioning and those with standard fitness preparation at the Nigerian Army School of Infantry, Jaji, Kaduna State. Methods: Sixty recruits will be divided into conditioned and standard preparation groups. Hypoxic exposure will be simulated using a normobaric hypoxic tent protocol over seven days. Haemoglobin, haematocrit, reticulocyte count, and arterial oxygen saturation will be measured at baseline, day 4, and day 7. Six-minute walk distance and lake Louise acute mountain sickness scores will track functional and symptomatic adaptation. Repeated measures ANOVA will compare group trajectories. Expected Outcomes: Physically conditioned recruits are anticipated to demonstrate faster haematological acclimatisation, better oxygen saturation maintenance, and lower acute mountain sickness scores than standard preparation peers. Conclusion: Findings will inform evidence-based pre-deployment altitude acclimatisation protocols for the Nigerian military. Keywords: altitude acclimatisation, military recruits, acute mountain sickness, haematological adaptation, Kaduna.