A Novel Application for Cognitive Evaluation in Mountain Ultramarathons: Olfactory Assessment

Area of Science:

• Sports Medicine
• Neuroscience
• Human Physiology

Background:

• Olfactory function serves as a biomarker for cognitive impairment.
• Mountain ultramarathon running presents extreme physiological challenges, including altitude, dehydration, and sleep deprivation.
• Assessing cognitive function in such demanding environments requires feasible and minimally invasive methods.

Purpose of the Study:

• To evaluate olfactory function in mountain ultramarathon (MUM) runners during the Tor des Géants race.
• To investigate the effects of prolonged physical exertion, dehydration, and sleep deprivation on olfactory function.
• To determine the feasibility of olfactory testing as a cognitive impairment biomarker in logistically challenging settings.

Main Methods:

• An Odor Identification Test was administered to MUM runners at three time points: before (T0), mid-race (T1), and after the race (T2).
• Olfactory function was also assessed in non-MUM athletes and sedentary controls for comparison.
• Statistical analyses were performed to correlate olfactory scores with race parameters, dehydration, and sleep deprivation.

Main Results:

• Olfactory function significantly decreased from before to after the race (T0 vs T2, P = .01).
• No significant relationship was found between olfactory function and race time or sleep deprivation.
• A negative correlation was observed between olfaction and total body water at mid-race (T1: rs = -0.427; P = .019), suggesting a link with dehydration.

Conclusions:

• Olfactory evaluation is a feasible and minimally invasive method for assessing cognitive impairment in extreme environments like ultramarathons.
• Prolonged physical activity in ultramarathons can lead to a decrease in olfactory function.
• Further research is needed to clarify the complex relationships between olfaction, cognition, and environmental factors such as sleep deprivation and dehydration.