I__. - International Military Testing Association

Acute High Altitude Exposure and Exercise
Decrease Marksmanship Accuracy
W.J. Tharion, B.E. Marlowe, R. Kittredge,
R. Hoyt and A. Cymerman
United States Army Research Institute of Environmental Medicine
Natick, Massachusetts 01760
ABSTRACT
Many moderate to high altitude areas occupy militarily .
strategic parts of the world. This study quantified the
effects of endurance exercise, acute altitude exposure (AAE)
and extended altitude exposure (EAE) (16 days at 4300 m), on
marksmanship performance. Sixteen experienced male marksmen
fired a de-militarized M-16 rifle equipped with a Noptel ST-
1000 laser system from a standing unsupported position at a
2.3 cm diameter circular target from a distance of 5 m.
Subjects were tested at rest and after a maximal 20.4 km
run/walk ascent from 1800 m to 4300 m, following AAE and EAE.
Sighting time (the interval between a signal light to fire and
trigger pull) and accuracy (distance of shot impact from
target center) were measured. Exercise and time at altitude
had independent effects on marksmanship. Sighting time was
unaffected by exercise, but was 8% longer following EAE (5.61
+ 1.25 set AAE vs 6.06 ?I 1.06 set EAE (mean i SD), ~C.05).
Accuracy was reduced 11% by exercise (3.63 ?: 0.69 cm at rest
vs 4.01 + 0.89 cm post exercise, ~