This video will help you interpret pain signals. Most tendon pain and some muscular pain can improve throughout your run as the tissues warm-up and gentle load is applied. This is often followed by mild pain after a run and worsening pain the following morning. Do not be fooled! This is different from your expected ‘muscle soreness’ that you will get the next day after doing a heavy gym workout. This step is crucial for runners and helps them differentiate a niggle from an injury.