Oedema of the extremities in runners

Swelling of the fingers or feet while running is a relatively common phenomenon among runners. Many athletes notice that their fingers become swollen, their rings feel tighter or their shoes seem narrower as the kilometres go by.

This phenomenon is most often a transient exercise-related oedema: an accumulation of fluid in the tissues causing localised swelling, most often in the fingers and feet and sometimes the ankles. It is generally benign and resolves after the run, even though it can be bothersome during training or racing.

During exercise, the body alters blood circulation to favour the working muscles and thermoregulation; this redistribution can lead to fluid accumulating in the extremities, particularly the hands and feet. When body temperature rises, blood vessels dilate to promote heat dissipation, which can also contribute to swelling.

The arms often remain bent and relatively still while running: this position can slightly limit venous return and promote fluid accumulation in the hands. In the feet, repeated impacts with the ground cause microtrauma and an increase in local blood flow, which can promote swelling over long distances.

Marathons, trail races and other endurance events are the situations in which swelling of the extremities is most often observed, especially during long runs and in hot or humid weather.

Certain factors can accentuate the phenomenon: long runs, heat or high humidity, excessive hydration, shoes that are too tight, or a lack of training.

Oedema of the extremities can present as swollen fingers, difficulty closing the hands, a feeling of tightness in the fingers, feet feeling tight in the shoes, or visible swelling of the ankles. In the vast majority of cases, the swelling disappears within hours of stopping exercise.

When to see a doctor?

Although it is benign in the vast majority of cases, certain situations warrant a consultation: swelling that persists for several days, significant pain, swelling limited to a single limb, or sudden onset without exertion. A doctor can then look for a circulatory or lymphatic cause if necessary.

Prevention relies mainly on adapting your equipment (slightly wider shoes for long distances, no rings, suitable socks) and on hydration guided by thirst rather than excessive drinking in advance. Moving your hands regularly during exercise and elevating your legs after running are useful additional measures.