July 16, 2025

Understanding and Mitigating Subterranean Operational Threats on Human Health and Performance: The Fatigue-Hormone-Mood Triad

With the advent of large-scale combat operations (LSCO) and contemporary threat groups’ use of underground tunnels, it is essential to understand the impact of subterranean military operations on human health and performance. Subterranean operations are not rapid in execution. Rather, warfighters can expect to spend days, weeks, and possibly months operating underground with limited access to sunlight, potable water, food, medical evacuation, and the resupply of rations and other military equipment. In brief, subterranean operations directly challenge human endurance, physiologically and psychologically. While subterranean operations are predicted to acutely strain and chronically suppress most, if not all, physiological systems of the body, this article focuses on the fatigue-hormone-mood triad.