Assessment of Central Nervous System Fatigue in Mountain Rescuers Following a Simulated Winter Rescue

The aim of this study was to analyze central nervous system fatigue through the critical flicker fusion threshold (CFF) in mountain rescuers after a simulated winter rescue. Fifteen rescuers (13 men and 2 women; age: 32.1 ± 8.5 yr) participated in the study, which was conducted at the Bormio ski resort in Italy. The simulation included ascending to a simulated victim (~75 kg), victim packaging, and descending using rescue stretchers or sleds. The rescuers’ CFF was assessed before and after the simulation, and their effort during the task was monitored through heart rate measurements. Throughout the simulation, the rescuers maintained an average intensity of 79.4 ± 6.7% of their maximal heart rate, with no significant differences in effort between the ascent and descent phases (p > 0.05). The CFF, measured as an indicator of sensory and cognitive fatigue, showed baseline values of 42.9 ± 2.0 Hz and post-simulation values of 43.6 ± 2.5 Hz, with no significant changes (p > 0.05). This finding contrasts with previous hypotheses suggesting cognitive decline associated with fatigue following high-intensity tasks. The lack of significant changes could be attributed to the rescuers' experience, which allowed them to regulate their intensity and employ effective strategies to avoid excessive fatigue. Additionally, the moderate environmental conditions (~7°C) likely reduced thermal strain, contributing to the stability of the CFF results. In conclusion, no significant differences in CFF were observed following the rescue simulation, suggesting that the protocol conditions and the characteristics of the studied group mitigated cognitive fatigue. These findings emphasize the importance of specific training programs to optimize the performance of mountain rescuers in real-life conditions.