Physical exertion has both beneficial and detrimental effects on cognitive performance, particularly cognitive control. Research into physical exertion under conditions of load carriage
is particularly important given that military
personnel and first responders must perform optimally under such combinatorial physical stressors. The present work sought to characterize cognitive control as a function of physical exertion and load carriage
in a military
Thirty-one active-duty soldiers underwent a 4-h operationally relevant and fatiguing scenario that included two 1-h foot marches under load carriage
conditions of 8.8, 47.2, 50.7 kg on each of three separate days. During each foot march, they completed five 5-min blocks of an auditory go/no-go task of response inhibition.
Results showed that response inhibition declined with increasing load carriage
and physical exertion, as evidenced by lower proportion of correct responses, higher proportion of false alarms, and lower response sensitivity between all three load conditions, particularly upon successive foot marches and time blocks within each foot march.
The results support previous laboratory-based work on load carriage
and physical exertion and suggest that deteriorations in cognitive control witnessed in laboratory settings are more pronounced within realistic operational scenarios akin to those encountered by military
personnel and first responders.