On a long run or after a big race, you may notice that your hands are swollen or your fingers look bigger and feel tighter. Well, you’re not alone.
A 2011 study examined the prevalence of this exact problem.
Researchers found that of the more than 1,000 people they analyzed, about one in four reported post-ambulatory hand swelling (aka, that same sensation you can get after some physical activity).
They also found swollen hands while running or walking is more prevalent in women. (We have walking and running workouts in the Aaptiv app!)
Here, we break down more about why our hands swell during running and ways to alleviate it.
What exactly causes swollen hands while running?
It’s easy to assume that you may be dehydrated so your body is holding on to water, which results in swollen hands.
You are running for extended periods of time, after all, so dehydration isn’t out of the question. But actually, it’s the opposite—and it has more to do with circulation than water retention.
“Some people’s circulatory systems respond differently to the increased energy we create [during a workout],” says Aaptiv Trainer Benjamin Green.
“The blood vessels expand in the hands or fingers when our core temperature increases, which can create swelling. Simply, increased blood flow will affect athletes in different ways.”
Often, this widening of the blood vessels occurs because blood flow can decrease in the hands and fingers as you work out, so the vessels expand to try to get more blood to the surface of the skin, says Edward Laskowski, M.D., co-director of Mayo Clinic Sports Medicine and professor in the department of physical medicine and rehabilitation. The widening of the vessels and the extra blood flow there can cause swelling.
Another factor: consuming too much H2O on race day. “Drinking too much during a long race can lower your sodium level by dilution,” Laskowski says. “A low sodium level, or hyponatremia, can cause swollen fingers.”
Keep in mind: Hyponatremia can be a serious condition. Symptoms can range from swollen fingers to confusion and vomiting.
So, stay aware of your physical state and listen to your body during long runs. Hand swelling, generally speaking though, is fairly common and shouldn’t be too much cause for alarm.
What can I do about it?
Unfortunately, there’s not much you can do to prevent it, Laskowski says. It shouldn’t affect you negatively, except that it’s uncomfortable.
To ease the discomfort, he suggests taking off any rings, doing arm circles, or alternating spread fingers and clenched fists.
For top workouts from the best trainers in the world, check out Aaptiv. We’ve just added new classes you’re going to love.