Ed asks: I saw high school cross-country runners lying on the ground after a practice with their feet propped up on a tree. Is there any merit to doing this?
That group of runners has learned either from their coach or from their own personal experience that the best way to prevent passing out after a hard run is to prop your legs up.
One of the causes of collapse following a distance run or race is exercise-associated postural hypotension. This is caused by the pooling of blood in the lower extremities as the leg muscle contraction associated with running stops squeezing the blood back to the heart. The blood vessels are dilated to maximize blood flow to the muscles during exercise, and the dilatation does not reverse as quickly as the blood flow. This can leave a runner with less blood flow to the brain, which can cause them to collapse.
“Legs up” is a common self-treatment and used to prevent exercise-associated collapse in medical tents around the world. There are other reasons for collapse like heat stroke, hyponatremia, and cardiac arrest; fortunately these conditions are relatively rare.
At the Medtronic Twin Cities Marathon, we use chaise longues to elevate the legs. We place a runner's head at the foot end of the lounger and the runner's legs at the head end. We raise the head end and lock the legs in an elevated position, gradually lowering the angle until the runner can lie flat and eventually sit without symptoms. It beats lying on the ground next to a tree, especially when the temperatures are low.
