What is the lymphatic system and how does exercise affect it?

Arteries 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-group triathlete 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.

Does exercise improve the lymphatic system?

Exercise is like giving your lymphatic system a gentle nudge to do its job better. Unlike the circulatory system, which has the heart to keep blood moving, the lymphatic system doesn’t have a central pump.

Instead, it relies heavily on muscle contractions and body movement to push lymph fluid along its pathways. When you walk, stretch, or even just with light movement, you’re essentially helping your body flush out cellular waste, circulate immune cells, and keep everything flowing smoothly.

World champion and GP Craig Dale confirms this, “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.”

The beauty here is that you don’t need marathon-level effort to see benefits. Gentle activities like yoga, swimming, or even a brisk walk can be powerful enough to get the lymph moving.

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 shows improvement to lymph function in obese individuals.

What are signs of poor lymphatic drainage?

When the lymphatic system gets a little sluggish, your body tends to leave clues—though they’re often easy to dismiss at first. Swelling in the arms, legs, or ankles (sometimes called lymphedema) is one of the most obvious signs, since fluid isn’t draining efficiently.

You might also notice that your skin feels puffy, tight, or heavier in certain areas. Other red flags can include frequent infections, slow-healing wounds, or even a sense of general fatigue that doesn’t quite match your activity level.

Beyond the physical, poor lymphatic flow can sometimes show up as brain fog or a sense of being run-down, since waste products aren’t being cleared as effectively.

Some people also experience skin changes like acne flare-ups because the system that helps filter out toxins isn’t keeping pace.

While these signs don’t always point directly to lymphatic trouble, when they cluster together, it’s worth paying attention.