Exceptions in children include Myocarditis, which increases the risk of sudden cardiac death Hypertrophic cardiomyopathy, in which increases in heart rate can increase risk of sudden cardiac death Acute splenic enlargement or recent infectious mononucleosis (Epstein-Barr virus infection) because splenic rupture is a risk Symptomatic or persistent fevers, which may decrease exercise tolerance, increase risk of heat-related disorders, and be a sign of serious illness Possibly significant diarrhea and / or recent significant vomiting because dehydration is a risk Exceptions in adults include Angina pectoris Recent myocardial infarction (within 6 weeks) Known aneurysms in the brain or large vessels Relative contraindications are more common and lead to recommendations for precautions or for participation in some sports rather than others, for example: People with a history of frequent and easily triggered dislocations or multiple concussions should participate in noncollision sports.