The Collapsed Endurance Athlete: Differential Diagnosis, Red Flags and Immediate Management - A Narrative Review

Abstract

Introduction and purpose. Collapse during or immediately after endurance exercise is a common presentation at mass-participation events, but the clinical spectrum ranges from transient post-exercise hypotension to cardiac arrest, exertional heat stroke and exercise-associated hyponatremia. This review presents a practical, problem-oriented approach to the collapsed endurance athlete.

Materials and methods. A narrative review was developed from PubMed/MEDLINE-indexed literature, consensus statements and major endurance-event cohorts. Priority was given to evidence addressing triage, exercise-associated collapse, heat illness, hyponatremia, cardiac arrest and on-site emergency care.

Results. Timing of collapse, level of consciousness, breathing pattern, core temperature and focused point-of-care assessment help distinguish uncomplicated post-exercise collapse from time-critical disease. Collapse during exercise, persistent altered mental status, abnormal breathing or circulation, marked hyperthermia, neurologic features and suspected cardiac disease should be treated as red flags. Management should be directed by the most likely physiology while immediately life-threatening conditions are excluded.

Conclusion. The collapsed endurance athlete should initially be approached as an undifferentiated emergency until immediately life-threatening causes have been excluded. A structured event-side pathway may reduce diagnostic anchoring and treatment delay, although prospective validation of such algorithms remains limited.