Thank you for your question. The question was not complete, however, I am assuming 9I hope correctly), that you were questioning your son running the marathon while on Concerta.   Stimulant medication can cause a spike in blood pressure or heart palpitations, however, no direct connection has been determined, if the person taking the medication did not have an underlying heart condition.   Additional information:   ADHD and Cardiovascular Risk   I hope this answers your question.   We wish your son well in running the marathon, what a great accomplishment for him. Please let us know how he does.   Eileen