Prolonged physical effort affects cognitive processes during special forces training

Abstract

This study aimed to investigate the effects of strenuous physical exertion on biomarkers of muscle damage, on physical and mental fatigue, and on cognitive processes. Seventeen military (males 24–40 years old) were tested cognitively at six time points, while they were progressively exhausted over the course of 102 h of continued operations. Three types of variables were analyzed: biomarkers of muscle damage [serum levels of creatine kinase (CK) and lactate dehydrogenase (LDH)], reported physical fatigue (PF) and mental fatigue (MF), and cognitive processes [(verbal reasoning (VR), numerical reasoning (NR) and spatial reasoning (SR) and short-term memory (STM)]. The results revealed significant increases in CK, LDH, PF and MF. On the other hand, we found significant decreases in VR, NR, SR and STM, which were negatively correlated MF. Our results show additional evidences about the impact of strenuous physical exertion on muscle damage, physical and mental fatigue, and cognitive processes.