I__. - International Military Testing Association

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at altitude, pi;;;: shooters als;ffired more quickly but less accurately.
He suggests feelings sickness and increased physical
symptomatology (acute mountain sickness) experienced in the first few
days of altitude exposure lead to lowered motivation to perform well,
presumably because of one's preoccupation with bodily discomfort. It is
also possible that subjects become impatient trying to maintain a good
aiming point with increased body sway encountered at altitude (Fraser,
Eastman, Paul and Porlier, 1987). They may then shoot prematurely,
resulting in the decrease in sighting time. It is speculated that
subjects may feel that taking additional sighting time would not improve
their accuracy. Another possibility may be that subject's time
estimation is affected. Time may seem to pass more quickly than it
actually does.
Upon acclimatization to altitude, individuals took 8% longer (Acute
Altitude Exposure 5.61 set vs Extended Altitude Exposure 6.06 set [means
of rested and fatigue conditions combined]) to sight the target. The
extra time apparently enables increased accuracy of shooting. Increased
respiratory rate is among the physiological adaptations that occur with
acute exposure to altitude, the faster the respiratory rate the more
breaths that are missed during the breath-holding phase of aiming and
pulling the trigger. This may increase discomfort associated with
breath-holding and thereby decrease sighting time.
While shooting at altitude, DCM, a measure of accuracy was 11%
greater after exercise (4.01 cm) than for the rested condition (3.63 cm)
[means of acute and extended altitude exposures combined]. Sighting time
was not affected by fatiguing exercise. In contrast to the present
results, Evans (1966) found accuracy was not affected by fatigue but
firing latency was. Other previous findings proposed increased body sway
after exercise as an explanation for reduced shooting accuracy of
soldiers after a forced march (Knapik, Bahrke, Staab, Reynolds, Vogel and
O'Connor, 1990), and biathletes after cross country skiing (Niinimaa and
McAvoy, 1983). Increases in heart rate resulting from intense aerobic
exercise also may impair shooting proficiency. Heart rate control by
beta-blockers (Kruse, Ladefoged, Nielsen, Paulev, and Sorenson, 1986;
Siitonen, Sonck and Janne, 1977) or biofeedback techniques (Daniels and
Hatfield, 1981) are possible remedies.
If military forces are to be prepared for deployment in a high
terrestrial environment, it may be advantageous to have them training .
routinely at high altitude. These results showed marksmanship accuracy
returned to normal after two weeks residence at altitude. For events
such as the biathlon and shooting competitions, athletes may benefit from
both acclimation to altitude prior to competition and routine training
at altitude.
Daniels, F.S. & Hatfield, B. (1981). Biofeedback. Motor Skills: Theorv
Into Practice 2, 69-72.
Dusek, E.R. & Hansen, J.E. (1969). Biomedical study of military
performance at high terrestrial elevation. Militarv Medicine, 134, 1497-
1507.
Evans, W.O. (1966). Performance on a skilled task after physical work
or in a high altitude environment. Perceptual and Motor Skills, 2, 371-
380.