Here’s Why Drinking a Lot of Water During a Marathon is a Terrible Idea

Photo by Kate Joie on Unsplash

It makes sense.

Drink a lot of water to replenish the sweat you have lost and to stay hydrated during the marathon.

However, runners don’t tend to realize when they have drank too much water to the point where fluid intake is more than he or she needs. You might be thinking too much water is vastly better than being dehydrated but in reality, it wreaks havoc on your body systems.

Kidneys come into play

When you drink more water than your kidneys can remove in the urine, too much water collects in your bloodstream. Too much water dilutes your blood hence reducing the amount of sodium in your blood. This condition is referred to as hyponatremia (hypo: less, natremia: sodium). Sodium is also lost in sweat making this condition even worse.

The human body always tries to keep things regulated and in order to preserve the remaining amounts of sodium in your blood, the body shifts excess fluid into cells and this causes swelling. This swelling is especially dangerous in the brain since the skull is unable to expand and this is most often fatal.

Symptoms of hyponatremia are vomiting, headache, confusion, muscle weakness, seizures, etc.

During strenuous amounts of exertion such as in a marathon, the body is already under a ton of stress and coupling this stress with hot temperatures that runners face and hyponatremia, it’s easy to see why it can have devastating consequences.

In the 2002 Boston Marathon, 13% of runners after completion of the marathon had hyponatremia. In the same marathon, a 28-year old runner collapsed during the race and died two days later due to hyponatremia. Hyponatremia is much more serious than it sounds and extra care must be taken during these marathons or other events to prevent such a scenario.

What to do?

For one, drink enough water that your body needs but not too much. This is easier said than done. However, a good rule of thumb is to drink small doses of water during a long run or marathon instead of gulping all of the water in one go. This will ensure that the body is able to handle this amount of water.

Additionally, the main problem was that sodium levels were low after drinking a lot of water and so if something can boost the amount of sodium in the blood, then this might be a potential solution.

This is where sports drinks such as Gatorade come into play.

A lot of sports drinks contain a bunch of electrolytes such as sodium, potassium, magnesium, and calcium and this is an excellent way to replenish these as they are lost in sweat.

Electrolytes are minerals that carry an electrical charge when they are dissolved in a liquid and they help regulate muscle and nerve function and maintain water balance.

Substituting sports drinks in place of water is a good way to ensure that runners are replacing the minerals and electrolytes that they are losing.

Hyponatremia is a very dangerous condition as we just saw as it not only depletes the body of an essential nutrient, but it can also be fatal if left untreated.

Drinking small doses of water through the marathon or using sports drinks while making sure that consumption of these drinks is inline with what your body requires goes a long way in ensuring that your body is well hydrated and regulated.



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Samir S.

Samir S.

Writing to Inform, Educate, & Teach | Obsessed with Health & Wellness |