ALTITUDE DECREASES MARKSMANSHIP
Swain, D. P., Moore, C. M., Ringleb, S. I., & Morrison, S. (2013). The effects of acute hypoxia on marksmanship. Medicine & Science in Sports & Exercise, 45(5), Supplement abstract number 2713.
This study evaluated the effects of acute hypoxia and physical exertion on marksmanship. At each of five simulated altitudes (162 m - sea-level; 1015 m - 1 Km; 2146 m - 2 Km; 3085 m - ,3 Km; 3962 m - 4 Km). Ss performed four shooting trials: at rest, immediately after a 60-second run with load, and twice more following 30-second rest periods. Arterial oxygen saturation, heart rate, and ventilation rate were recorded.
Increased altitude significantly decreased marksmanship. The shooting scores at 4 Km were significantly lower than those at all other altitudes. Specifically, shooting score at rest was 17.2 ± 5.6% less at 4 Km than at sea-level. The exercise task decreased shooting performance which somewhat improved in recovery trials. The shooting score at rest was significantly greater in all trials following exercise, decreasing 14.9 ± 3.8% immediately post-exercise at sea-level, and decreasing 24.3 ± 6.0% immediately post-exercise at 4 Km. Altitude and exercise both significantly reduced arterial oxygen saturation and increased ventilation rate. Heart rate did not change with altitude, but increased following exercise. There was a strong positive correlation (r = 0.84) between marksmanship and arterial oxygen saturation. There was a strong inverse correlation (r = -0.72) between marksmanship and ventilation rate, and a modest inverse correlation (r = -0.54) between marksmanship and heart rate.
Implication. Increasing altitude impaired marksmanship, with a threshold in the vicinity of 3000 m. Decreased marksmanship was closely related to decreased arterial oxygen saturation, which could decrease marksmanship by impairing cognition and increasing ventilation, the latter impairing aim by increasing movement of the chest wall.
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