IMMUNITY BOOST

QWhat is the lymphatic system and how can exercise affect it? Jennifer Watson

AArteries and veins are the motorways of the body, swiftly carrying all the stuff we need for life to where it’s needed, while also carrying some of the waste products to be removed or recycled. The lymphatic system is similar but can be thought of as the B-roads of the body. This network of vessels helps drain fluid away from tissues in the body, returning it to the main venous system in one of the large veins close to the heart. It’s for this reason that damage to the lymphatic system can cause swelling in the affected area.

The lymphatic system also plays a vital role in keeping us from getting ill. Dr and Great Britain age-grouper Duncan Birse explains, “Our glands are part of our lymphatic system and contain the white cells we need to fight infection. These ‘nodes’ effectively sieve the fluid that passes through them and when viruses, bacteria or other infections are detected, the white cells get to work killing whatever is attacking the body or removing cells that have been damaged. That’s why you get swollen glands with an infection – they are mobilising the immunity troops!”

Vital as these functions are, lymphatic traffic is slow on these B-roads as the fluid isn’t pumped by the heart. Instead, body movement helps to move fluid through the vessels so, says world champion and GP Craig Dale, “Exercise can promote this movement, particularly the return of lymph from the limbs, reducing excess fluid in the tissues and helping to reduce blood pressure.”

While overtraining impacts the immune system, according to one study endurance training improves not just lymph flow during exercise but also at rest, while another study showed improvement to lymph function in obese individuals. This suggests that appropriate exercise can improve the function of the lymphatic system and support immunity allowing you to train more consistently throughout the season. Joel Enoch