The common causes of Achilles tendon pain after exercise are Achilles tendon injury, Achilles tendonitis, heel osteophytes and so on. 1. Achilles tendon injury: After some running or jumping exercises, the Achilles tendon is repeatedly pulled, which causes the Achilles tendon tissue to be damaged and produces pain in the Achilles tendon after exercise. 2. Achilles tendonitis: the Achilles tendon itself may have chronic inflammation, and after some sports, the strong contraction of the Achilles tendon makes the chronic inflammation of the Achilles tendon have an acute attack, which produces pain. 3. Heel osteomalacia: It may be the degeneration of the bone that constitutes the heel, osteomalacia, the growth of bone compression to the nerves, the Achilles tendon, the Achilles tendon pain after exercise. There may be other reasons for Achilles tendon pain after exercise, it is recommended to go to the hospital in time to find out the cause and give treatment to the cause to avoid delaying the condition.