Influence of altitude and hydration status on soldiers of the VIII Mountain Brigade at high mountain level

Abstract

Introduction: exercising at high altitudes deserves special considerations when it comes to determining fluid requirements in athletes, especially in Army mountain troops. Maintaining a state of euhydration during physical activity is essential to avoid health complications. The aim of this research is to identify the hydration status of soldiers of the VIII Mountain Brigade of the Argentine Army based in Mendoza, Argentina in 2021.

Materials and method: descriptive, observational, longitudinal study. The sample consisted of 87 male soldiers. The data collected included the amount and type of fluid intake, urinary specific gravity by using a manual refractometer, percentage of weight change and subjective perception of thirst. Statistical analysis for qualitative variables was done with the χ2 test and 95% CI, quantitative variables were compared using the t-Student test.

Results: 96.5% of soldiers hydrated themselves with water. The mean fluid intake was 1.34±0.74 liters (L), with a maximum intake of 4 L and a minimum of 0.5 L. 36% percent of the sample presented a body weight loss of more than 2% at the end of the activity, the relative difference referred to the mean initial weight was 1.7±1.4%. At the end, 43% were classified as euhydrated and 29% as severely hypohydrated according to specific urinary gravity. According to the subjective perception of thirst at the end, only 14% of the soldiers were not thirsty.

Conclusion: the study showed that 64% of the soldiers maintained an optimal fluid replacement strategy, given that weight losses were limited to what was expected.