By Jason Koop, CTS Coaching Director and author of “Training Essentials for Ultrarunning”
Raising your legs above your heart used to be post-workout dogma, and even standard practice during downtime at any running practice or workout session. I have no idea how many hours I spent during high school and college lying on my back with my feet up on a wall in pursuit of post-workout recovery.
The concept was that lactic acid would drain from your legs, or that blood polluted with metabolic waste would otherwise pool in your legs, so elevating them facilitated the circulation of that bad stuff out of the legs and allowed fresh, oxygenated, nutrient-rich blood to take its place.
There may be some benefit to lying around with your legs elevated after a hard workout, but it’s not draining lactate or lactic acid from your leg muscles or preventing blood from pooling in your legs. Lactate produced during exercise is circulated throughout the body in your blood, and can be used by any muscle – including your heart – for energy.
In other words, the lactate you produced during your workout only accumulated in your legs because your leg muscles were the ones doing the hard work. It was immediately circulated throughout the body, and both during and after exercise it was broken down to usable energy in muscle cells. You don’t need to drain lactate from your leg muscles because it already happened, and because if it’s around your muscles will reintegrate it into normal aerobic metabolism and break it down for energy.
How about facilitating circulation?
Well, as a vascular surgeon pointed out, when you need to proactively assist the circulation of blood out of your extremities, that’s a medical problem. For a healthy person, your body is more than capable of circulating blood against gravity.
The flow of lymph and extracellular fluid, however, is more responsive to gravity. This is why ultradistance runners, some ultradistance cyclists, and otherwise healthy people on long plane flights sometimes develop puffy ankles. It’s not blood that’s pooling, it’s extracellular fluid and maybe lymph.
What Elevating Your Legs Can Do For You
Elevating your legs can help to reduce swelling. Compression garments may be helpful for prevention of such swelling, and pneumatic compression (Normatec boots) may also be helpful for reducing it once it is present. If notable swelling (cankles) isn’t present, elevating your legs won’t hurt but it may not be necessary. If you do elevate your legs, sit up or get up and walk around for a few minutes about every 15 minutes.
Dealing with Post-Ultramarathon Swelling
A lot of runners face lower-leg swelling during and after ultramarathons. A 2012 study by Cejka, et al. found that out of 80 subjects running a 100km footrace, 20 experienced increased foot volume, 18 experienced no change in foot volume, and 38 experienced reduced foot volume. When they looked at fluid intake and other body fluid measurements they concluded that the increase in foot volume correlated with runners with greater fluid intake. While this increased fluid intake wasn’t enough to lead to hyponatremia, they had essentially overloaded on fluid and/or experienced a decrease in plasma sodium concentration.
This is not to say that all cases of swollen feet during and after ultrarunning is due to excessive fluid intake, but it does indicate your hydration and nutrition strategies may contribute to the amount of swelling you experience. This is therefore something you can test and adjust in training to see if you can mitigate swelling through nutrition and hydration. Keep in mind, there is a difference between lower leg swelling and whole-body swelling. The latter may be more indicative of hyponatremia and should be of greater concern.
If you have swollen feet following your ultramarathon event, raising your legs above the level of your heart may help to reduce the swelling more quickly. However, as mentioned above, it is important to get up and walk around about every 15 minutes. Your leg muscles are very good at facilitating circulation against gravity, and periods of light walking is also better than complete rest for reducing joint stiffness.
Athletes who have been around a while will recognize the old adage: “Why stand when you can sit, why sit when you can lie down?” When it comes to post-workout recovery, getting athletes to simply do less and rest more is a win. Sitting or lying down, whether your feet are elevated or not, still means you’re resting. If you have the opportunity, taking a nap would be even better!
Cejka, Caroline, et al. “An Increased Fluid Intake Leads to Feet Swelling in 100-Km Ultra-Marathoners – an Observational Field Study.” Journal of the International Society of Sports Nutrition, vol. 9, no. 1, 2012, p. 11.