To investigate the differences in physical fitness and physiological indexes of male soldiers stationed at different altitudes and to analyze the determinants of physical fitness of these soldiers.

A total of 13648 male soldiers at different altitudes were included, whose results of annual military physical assessment and physiological indexes in 2023 were collected and comparatively analyzed.

The 3000-meter running performance,30-meter × 2 serpentine running performance and resting blood oxygen saturation of high-altitude soldiers gradually declined with the increase of altitudes. The pull-up performance dropped significantly when the altitude > 2000 m. Soldiers ≥30 years old demonstrated a marked decline in physical fitness across different training programs. Moderate altitude acclimatization was conduciveto the recovery of physical fitness of soldiers, while exposure to high-altitude environment ≥5 years led to overall deterioration.

The high-altitude environment significantly impacts the aerobic endurance, speed, agility, and strength of soldiers. Altitude ≥4000 m, age ≥30 years, and prolonged exposure ≥5 years may contribute to the decline in physical fitness of soldiers.