Leg tummy is the bulging part at the back of the calf. Leg tummy pain is usually caused by excessive exercise, cold legs, lumbar disc herniation and other reasons. 1. Excessive exercise: standing for a long time, walking activities, regular running and jumping and other excessive exercise, easy to lead to muscle spasms in the area of the stomach of the legs, lactic acid buildup is excessive, the emergence of pain in the stomach of the legs, you can take appropriate rest to let the calf muscles relax. 2. Cold legs: Cold leg muscles lead to local muscle spasms causing discomfort, which may lead to pain in the legs and stomach, you should pay attention to keeping warm and avoiding the legs from catching cold. 3. Lumbar disc herniation: Lumbar disc herniation causes pain in the lumbar region when the nerve roots are compressed, and the pain radiates to other parts of the lower limbs, resulting in pain in the legs and stomach. If the pain is serious and cannot be relieved, you should consult a doctor for a clear diagnosis and treatment, and avoid excessive exercise and cold legs.