Cognitive Performance and Physiological Changes under Heavy Load Carriage

This study was designed to examine the relationship between load carriage, cognitive performance, and perceived workload. Participants carried equipment typically worn in combat, walked on a treadmill (simulating a dismounted patrol) for two hours, and concurrently performed a series of cognitive tasks similar to those required in combat (e.g., detection, recognition, working & spatial memory, and communication). All participants completed three two-hour sessions wearing a 0, 98 or 135 lb combat load. Physiology (kcals) highly correlated (r = 68, p .01) with subjective rating of strenuousness. Results show that infantrymen can maintain a high level of physical performance over time; but at a cost to cognitive performance (p .05). In addition, and potentially of great operational significance, is that after removing the 135 lb weight and resting for 5 minutes, cognitive performance did not return to baseline levels. Potential mitigations and implications of these results will be discussed. The original document contains color images.