Endurance racing subjects horses to extreme physical demands over distances of 50–160 km. Welfare science focuses on metabolic exhaustion, lameness, and cardiac stress. FEI regulations mandate veterinary gates every 20–40 km with mandatory rest periods and trot-up assessments. Studies indicate elimination rates of 20–40% in longer rides, primarily for metabolic or lameness issues. Critics advocate for stricter conditioning requirements, slower pace limits, and mandatory pre-event fitness certifications. Welfare improvements include real-time GPS tracking, heart rate monitoring, and compulsory cool-down protocols.