Effects of Carbohydrate Intake and Load Bearing Exercise on Rifle MarksmanshipPerformance

摘要

The combined and separate effects of load bearing exercise and dietarycarbohydrate (CHO) levels on rifle shooting were examined. The study consisted of three phases. During each phase participants (15 male soldiers) were randomly and blindly administered one of three experimental ration diets, 250 g, 400 g, or 550 g CHO diet for a four day period. Protein and total kcal remained constant with the CHO and fat contents varying. Participants fired a disabled M-16 rifle equipped with the Noptel ST-1000 marksmanship simulator before and after strenuous load bearing exercise. The exercise consisted of marching on a treadmill for up to 4 hr at a rate of 3.5 mph while carrying a weight of 45 kg. Participants shot at a simulanted 100 m target for both speed and accuracy and for accuracy only. Analyses of variance showed shot group tightness (SGT) was significantly impaired (p<0.05) following exercise when shooting for accuracy only. Sighting time was reduced following exercise (p<0.05). No main effect of CHO level occurred for any marksmanship measure. A significant diet by exercise interaction effect for SGT (p<0.01) existed when shooting for accuracy only. A significant deterioration in SGT occurred after exercise while consuming the 250 g CHO diet while no significant differences existed pre to post exercise for the 400 g or 550 g CHO diets. The results of this study indicate that soldiers required to march with loads of 45 kg can expect to display impairments in marksmanship.... Marksmanship, Carbohydrates, Load carriage, Physical exercise, Fatigue, Military tasks.