Does Exercise Help Your Immune System?

Exercise is beneficial in so many ways -- stronger lungs and heart, stronger muscles, better balance, increased stamina and endurance. It also impacts your lymphatic system on several levels, resulting in better health and immunity.

Most of your lymphatic vessels, a mesh of microscopic pathways like veins, are located just under the skin, to protect you from external disease-causing organisms that might penetrate your body and cause disease. This network of lymphatic vessels is surrounded by fibrous connective tissue which connects the lymphatics to your skin and muscles. Regular, low-intensity movement such as walking at a gentle pace makes your skin move, and this pulls on the connective tissue surrounding the lymphatics -- causing small windows in the lymphatics to open so that tissue fluid can enter. Fluid that enters the lymphatics at this level is processed in your lymph nodes where white blood cells destroy anything that might cause harm.

More intensive exercise also affects the lymphatics, at the deep level in the abdomen and chest. When you exercise with more intensity, you breathe deeply, completely filling and emptying your lungs with each breath. The largest lymphatic vessel -- the thoracic duct -- arises in the abdomen and is located in the chest. Each breath squeezes the thoracic duct, causing it to empty into veins near the neck. Then when you exhale, more lymph is pulled into the thoracic duct from the lymphatic trunks located deep in the chest and abdomen.

When you inhale deeply, during intensive exercise, for instance, your diaphragm presses down on your abdominal organs, moving them downward and forward in the abdomen.. When you exhale, the pressure relaxes and the organs move back into their resting places. This constant movement is a kind of innate organ massage and it stimulates lymph circulation in the organs and in the abdominal cavity.

However, extremely intense exercise, for instance the kind of workout a high-level athlete might perform to get ready for competition, can actually suppress your immune system for a few hours after the workout. Unless you are at that level of competition, try to work at about 75 percent of your full capacity rather than pushing yourself to the point of exhaustion. If you do work out that hard, be aware that for a few hours afterward you will be more susceptible to minor illnesses like the common cold.