Back pain after practicing legs should be treated with general treatment, physical therapy, medication, etc. depending on the cause. Common causes include excessive exercise, lumbar muscle strain, lumbar intervertebral disc herniation and so on. 1. Excessive exercise: the body produces a large amount of lactic acid during the process of practicing legs, which induces lumbar muscle pain, it is recommended to rest more, warm up before exercise, and stretch after exercise. 2. Lumbar muscle strain: prolonged sitting or standing, the lumbar muscles for a long time in a tense state, easy to strain, resulting in lumbar pain, can be into the massage or infrared baking lamp treatment, but also oral ibuprofen extended-release capsules, pain relief. 3. Lumbar disc herniation: rapid rotation of the torso, long jump and high jump, resulting in the nucleus pulposus of the intervertebral disc compression of the nerve, pain. Diclofenac sodium extended-release tablets can be taken to relieve pain. There may be other reasons for back pain after practicing legs, it is recommended to go to the hospital in time, the above medication is recommended under the guidance of a doctor.