Q. Why do my feet and hands swell during and after endurance activity?
A. The swelling is edema (accumulation of fluid between the cells) and it definitely indents when pushed on. When you run, blood flow is increased to the working muscles. Along with this increase in blood flow comes an increase in capillary permeability. Tissue damage also leads to changes in vessel permeability (just like when you swell after an injury). When you are running, blood flow is great enough (in most cases) to allow removal of the leaking fluid, but when you stop, it is not.
There is a bunch of factors that causes tissue trauma in aerobic endurance workouts, making tissue all the more sensitive to free radicals. Tissue trauma happens in all organ systems of our body. It results in membrane breakdown of cells. When we run in good shape from the start to the finish, trauma at least occurs in muscles and capillaries. Radicals bind to the cell membrane, start the breakdown processes. The result is that in a vicious circle leaking holes open up in the membrane, which let water, electrolytes, and if big enough even plasmaproteins pass into the space outside the vascular system, between the cells. This is called edema.
When edema occurs during and immediately after a run, but disappears within 3 days, it is mostly based on leak of water and electrolytes. The capillary membranes heal within 1-4 days.
- Trauma is caused in endurance aerobic workouts whatever the training level or pace is. However, sufficient training and reasonable pace decreases the extent of trauma (tissue damage). Antioxidants like Vit. E and C help coping with the free radicals.
- Prevention of dehydration does not stop at the finish line. Rehydration and adequate salt intake is important for the next 48 hours.
- Avoid alcohol. Not only is the liver essential for fueling and for metabolizing lactic acid, but also for resynthethis of plasma proteins lost due to leak during and after the event.
- Eat enough high quality protein after the event.