The pain in the left abdomen after exercise is due to insufficient or no warm-up activities before strenuous activities. During strenuous activity, the muscles enter a state of tension, but the internal organs are too lazy to move immediately to meet the nutrition and oxygen needed for muscle activity, which makes the respiratory muscles tense and cramp, or when the oxygen demand of physical activity increases, the breathing is inappropriate, just speeding up the breathing frequency and shallow breathing will also make the respiratory muscles tense and cause cramps. Long-term non-participation in sports activities or cold weather, as well as excessive sweating lead to low sodium chloride content in the body, which can also cause "barbecued pork". "Diverging qi" is also called acute chest rib pain. When "cross-qi" occurs, the respiratory muscles spasm, which stimulates the receptors in the respiratory muscles and causes pain. The main respiratory muscles of human body are intercostal muscle and diaphragm. When intercostal muscle spasms, there will be pain on both sides of the chest. When the diaphragm spasms, there will be pain under the left and right ribs. The methods to stop and prevent "out of breath" are: 1, changing shallow breathing, deepening breathing, slowly and deeply exhaling, and forcibly exhaling, so as to inhale a lot of air, meet the needs of oxygen during exercise, relax breathing muscles and eliminate pain. 2. Adjust the breathing rhythm and combine the breathing rhythm with the running frequency, so as to achieve two steps and one breath or three steps. 3. If the above methods can't eliminate the pain, you can take a deep breath, hold your breath, forcibly buckle the pain on both sides of the chest or under the ribs, and then take a deep breath slowly. Repeated several times can gradually relax the respiratory muscles and relieve spasms. 4. Before strenuous activity, prepare for the activity, so that the respiratory muscles can gradually adapt to the faster contraction frequency, so as not to cause convulsions. Try to breathe through your nose when exercising in winter. If you breathe through your mouth, open your mouth half way to let cold air enter your mouth through your teeth to prevent excessive stimulation.