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- A recent study in Applied Physiology, Nutrition, and Metabolism found that a majority of ultrarunners believe sodium supplements should be available at aid stations.
- However, sodium supplementation does not prevent cramping, dehydration, and nausea, previous research has found.
- Plus, sodium will also be naturally replenished in the body by a typical race diet—and taking in too much could lead to overhydration.
Ever search around an aid station at an ultra or a marathon for some sodium supplements? If so, you’re not alone: The majority of ultrarunners wish these supplements were provided to them—even though they may not bring the benefits they think.
In the study, published in Applied Physiology, Nutrition, and Metabolism, researchers polled 1,100 ultrarunners and asked them whether they believed sodium supplements should be supplied to runners during their races. They found that 66 percent of participants believed that sodium supplements should be made available at ultramarathons.
Ultrarunners who were in favor of the supplements said they wanted them available to help prevent exercise-associated hyponatremia—low levels of sodium in the blood—and muscle cramping.
Of those who said that sodium supplements should not be made available? The majority of responses (85 percent) said it was because runners can provide their own. Twenty-eight percent said it was because they are not necessary, and just 12 percent said that it puts runners at risk for thirst and overhydration.
According to study author Martin Hoffman, M.D., professor of physical medicine and rehabilitation at the University of California Davis, there is a lot of misinformation about just how necessary sodium tablets at aid stations area during an ultramarathon.
“As an ultramarathon runner, I’ve seen this behavior firsthand for decades. The work simply documents that our educational efforts need to continue,” Hoffman told Runner’s World.
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Hoffman’s previous work , published in Sports Medicine, found that contrary to popular belief, sodium supplementation does not prevent cramping, dehydration, and nausea. Plus, findings indicate the excessive sodium intake—which can lead to the gross-but-harmless white caking on your clothes when you sweat—could also stimulate overhydration, which can lead to exercise-associated hyponatremia. Yep, the same condition people believe can occur without the supplements can actually be triggered by taking in too much sodium.
Excess sodium causes your body to retain fluid and overhydrate—you feel thirstier, produce less urine, and excrete more sodium in that urine. That ends up causing the low sodium blood levels.
“Basically, you drink more, retain the fluid, and lose the sodium,” he said.
Symptoms of hyponatremia include nausea and vomiting, headache, confusion, and muscle weakness or cramps. If hyponatremia becomes severe, there is risk for seizures, coma, and even death.
Research just doesn’t support the benefit of taking sodium supplements for ultrarunners, Hoffman says. Sodium in itself is not a fuel source that will help power your run, and even though a lot of sodium may be lost in sweat during a long bout of exercise, a typical race diet will generally provide enough to make up for it. This can through fuel like sports drinks, chews, or gels that already contain sodium, or foods found at aid stations like pretzels or sandwiches.
“Other sodium that is stored in the body in bone and connective tissue can be mobilized to support that deficit,” Hoffman said. “Our work has shown that no sodium supplements are required for an ultramarathon in hot conditions lasting 15 to 30 hours.”