CAFFEINATED GUM MAINTAINS VIGILANCE, MARKSMANSHIP, AND PVT PERFORMANCE DURING A 55 HOUR FIELD TRIAL

This study was designed to evaluate the effectiveness of caffeine gum in maintaining performance on a variety of military tasks during a 55 hr field training exercise with restricted sleep. A secondary goal was to correlate performance on a hand held computerized Psychomotor Vigilance Test (PVT) with actual performance of a field task. Thirty Canadian soldiers volunteered to participate in this study and were divided into 4 sections. After receiving 3 hours of sleep during the first night, they were awake for 30 hours. Two of the four sections received caffeine gum (CAF) and the other two groups a placebo gum (PLA). On the evening of Day 2 and morning of Day 3 subjects in CAF received 100 mg @ 2145 (Day 2), 200 mg @ 2345 (Day 2), 100 mg @ 0145 (Day 3), and 200 mg @ 0345 (Day 3). The placebo group always received the placebo gum. There were two test blocks from 2200-0200 (early night) and from 0200-0600 (late night). In each of the two test blocks subjects completed a live fire marksmanship/vigilance task and an Urban Operations Vigilance Task (UOVT). The PVT was administered prior to and after marksmanship and the UOVT. Performance on all of the field tasks significantly declined during the second night of the exercise with placebo. In contrast, subjects who received the caffeine gum maintained their performance on the marksmanship task and in the FIBUA task. These results demonstrate the potential utility of caffeine as a fatigue countermeasure in the operational environment.