Ultra-endurance races (ultra-marathons) take place under extreme environmental conditions, over long distances, involving prolonged physical activity and multiple psychological and physiological challenges.

These extreme conditions expose runners to a wide range of emotions-both pleasant and unpleasant-that can influence their performance, fatigue, and perception of exertion.

Emotional intelligence and emotional regulation appear to be key determinants of emotional trajectories and performance in these contexts. Previous research shows that high levels of emotional intelligence and adaptive emotional regulation strategies are associated with functional emotional trajectories and better performance, whereas maladaptive strategies are linked to dysfunctional emotional trajectories and reduced performance.

Furthermore, defense mechanisms constitute a complementary approach to emotional self-regulation. They can be adaptive or maladaptive and influence how runners cope with emotions and psychological stressors during competition.

Longitudinal studies conducted to date have primarily explored post-race emotional trajectories in relation to emotional intelligence, without examining the impact of defense mechanisms on emotional dynamics during the race. Furthermore, few studies have examined the mediating role of emotional intensity between emotional regulation and perceived performance, and even fewer have adopted an approach that integrates physiological indicators such as heart rate or heart rate variability.

Thus, this study lies at the intersection of sports psychology, emotion, and physiology, and aims to fill these gaps by exploring:

1. the influence of defense mechanisms on emotional dynamics and physical and mental fatigue during an ultra-endurance race, and
2. the mediating role of emotional intensity on the relationship between emotional regulation and perceived performance.

The objective of this study is to examine how certain psychological mechanisms used to cope with difficult situations influence the evolution of emotions experienced by participants during and after a 120-kilometer ultra-endurance race.

A descriptive, non-interventional, longitudinal exploratory study of healthy, able-bodied participants of both sexes, based on the completion of self-administered questionnaires on a tablet before, during (kilometers 16, 41, 56, 68, 89, and 112) and at the finish line (120th kilometer) of the "Ecotrail de Paris Ile de France 120 kilometers" ultra-trail race taking place on March 21, 2026

Inclusion Criteria:

• Individuals who have agreed to participate in the study
• Age ≥ 18 years
• Smartwatch capable of measuring heart rate and transmitting this data
• Subject with no significant medical history (chronic pulmonary disease, heart disease contraindicating Class IIIC exercise according to the Bethesda classification, pharmacologically treated hypertension, or significant chronic inflammatory disease)
• Participation in the "Ecotrail de Paris Ile de France 120 kilometers" ultra trail taking place on March 21, 2026.

Exclusion Criteria:

• Persons under legal guardianship or conservatorship
• Persons under judicial protection
• Persons deprived of liberty
• Persons not enrolled in a social security system
• Women who are pregnant or breastfeeding at the time of enrollment

Healthy, able-bodied participants of both sexes, participating to the "Ecotrail de Paris Ile de France 120 kilometers" ultra-trail race taking place on March 21, 2026