Lower back pain after exercise without pain can be the occurrence of lumbar dorsal myofasciitis, lumbar muscle strain, rheumatoid, ankylosing spondylitis and other diseases. 1. Lumbar dorsal myofasciitis: lumbar dorsal myofasciitis is mainly due to lumbar dorsal myofascial exertion and cold, resulting in chronic aseptic inflammation of the local fascia, when the activity can accelerate blood circulation, promote the dissipation of inflammatory substances, which may reduce the pain symptoms. 2. Lumbar muscle strain: lumbar muscle strain can appear when the symptoms of lumbar pain, after a while in the activities of the pain symptoms can be improved, mainly due to the activities help to relieve local muscle tension, can improve the symptoms of lumbar stiffness and discomfort. 3. Rheumatoid: morning stiffness is a characteristic manifestation of rheumatoid arthritis, mainly due to the reduction of movement caused by swelling of the tissues around the affected joints, activities can promote the absorption of edema fluid. Rheumatoid involved in the waist, may appear after activity pain relief performance. 4. Ankylosing spondylitis: ankylosing spondylitis involving the lumbar region can appear pain symptoms, when the lumbar region after the activity, can accelerate blood circulation, can promote the dissipation of inflammatory substances absorbed, help to relieve the pain and discomfort symptoms. There may be other reasons, if long-term back pain, we recommend that patients consult a doctor in a timely manner, after a clear diagnosis, follow the doctor’s instructions for treatment.