Changes in cognitive performance during a 216 kilometer, extreme endurance footrace: a descriptive and prospective study

Two subjects participated in a 216 km ultramarathon with outside temperatures above 50 degrees C while several physiological and psychological parameters (cognitive performance assessed by a mental calculation task and an attentional task, subjective bodily experience, and lactate level) were evaluated throughout the race. Severe stress from dehydration, sleep deprivation, and total physical exhaustion are combined in a unique manner, allowing evaluation of their effects in a range far outside that obtainable in a laboratory setting. During the race the subjects answered a questionnaire about their actual bodily experiences, underwent 8 medical examinations, and performed two cognitive tests approximately every 35 kilometers. Analysis showed cognitive performance did not decrease steadily in a simple and gradual way but reached a peak in the morning of Day 2 after a short sleeping period and then decreased. In the early morning of Day 3, in general cognitive performance exhibited the worst results but increased differentially between the subjects again in the last test 1 km before the finish line.