Running hurts…..especially marathon running. An ache or pain is usually an injury if it persists for more than 5-7 days in the same pot. If you have pain > 5-7 out of 10 (10 being I’m dying and 0 being no pain); you should seek immediate attention. If you have a mild ache that is nagging more than a week, get it checked out before it becomes a serious injury.