According to Tim Noaks there are 4 grades that injuries progresses through.
1.) An injury that causes pain after exercise and is often felt some hours after exercise has ceased.
2.) An injury that causes discomfort, not yet pain, during exercise, but that is insufficiently severe to reduce the athlete’s training or racing performance .
3.) An injury that causes more severe discomfort, now recognized as pain that limits the athlete’s training and interferes with racing performance.
4.) An injury so severe that it prevents any attempts at running. Use this as a guide to know how severe your injury is in order to take action. Know yourself and get to know your body!