Skip to content
Does Overhydration Cause Performance Problems

Does Overhydration Cause Performance Problems

Who would have thought drinking too much water could pose a health risk?

We need to drink enough water to keep our body functioning — if we drink too much, or too little, there are significant issues to deal with. While many find it hard to stay hydrated, some people go overboard on the water. This is often referred to as "water intoxication," or hyponatremia.

Related - Calculate Your Daily Water Requirements

Hyponatremia is where an individual consumes an extreme quantity of water too quickly.

Our bodies are made up of up to 60 percent water, so we understand the importance of drinking plenty of water. Unfortunately, drinking as much water as we possibly can isn't the answer. Drinking too much water can cause as many harmful side effects like dehydration.

What is Hyponatremia?

This is a fancy medical term for the sodium imbalance in the body. Sodium imbalances can happen when you drink excessive amounts of water and flooding your cells with water. Salt is an electrolyte that regulates how much water will go in and out of your cells. Once your sodium levels get diluted, it starts to interfere with organ function.

Water intoxication occurs when your electrolytes are dangerously out of balance.

Symptoms of Overhydration

  • Nausea
  • Headache
  • Confusion
  • Muscle cramps
  • Drowsiness
  • Seizures
  • Coma

Drinking water isn't the only way to experience overhydration. Remember, overhydration is simply an excess of water in the body. Individuals who have a disorder that decreases your body's ability to excrete water or increases your body's tendency to retain water can both suffer from overhydration.

Funny enough, drinking too much water alone is rarely the cause for overhydration due to the kidney's ability to excrete excess water. Many times there are no symptoms, but in severe cases, people have become confused or even have seizures.

If left untreated, or misdiagnosed as dehydration, hyponatremia can progress to brain swelling, seizures, pulmonary edema, comatose, cardiorespiratory arrest, or even death.

Overhydration occurs when the body takes in more water than it loses.

Athletes are particularly susceptible to overhydration due to drinking excessive water to avoid dehydration. Remember, too much water without enough sodium can be harmful. Generally, low sodium levels in the body creates hyponatremia. In order to exceed your body's ability to excrete water, a young adult with normal kidney function would need to drink more than six gallons of water per day on a daily basis.

Overhydration is more common in individuals whose kidneys do not excrete urine normally — people who have a heart, kidney, or liver disorder, those who take certain antidepressants and other medications are susceptible to overhydration.

While it is possible to drink too much water, it is usually other medical conditions and medications that throw off the balance of our electrolytes.

What if You Are Thirsty?

When you get thirsty, that's your body's way of telling you that it needs water. Sometimes, though, it can signify some other health issues. It's normal to get thirsty sitting in a hot room or while exercising.

Other medical problems can cause thirst, especially when it happens when you aren't doing anything active. Extreme thirst is generally associated with diabetes, so if you experience extreme thirst, you should visit a healthcare specialist to get checked out. Both Type 1 and Type 2 diabetes can cause extreme thirst. This isn't a telltale indicator you have diabetes, but it's a serious symptom you shouldn't ignore.

Diabetes causes a build-up of excess glucose in your blood. In response to this, your kidneys constantly try to filter it out in your urine. Since you are dehydrated, you keep drinking more and more water in a vicious cycle. This could lead to overhydration.

How Much is Too Much Water?

There's really no set amount for how much water you need to drink. A good rule of thumb is to drink if you are thirsty.

Athletes will only need to drink as much water as they can sweat out during a high-intensity activity like a marathon. It may be wise to alternate between water and a sports drink so that you can replenish lost electrolytes and keep from drinking an excessive amount of water.

Your body absolutely needs water to perform optimally, so hydration is extremely important, so reach out to your doctor if you always seem thirsty — it could be an underlying problem that needs to be addressed.

The American College of Sports Medicine recommends an athlete to drink four to eight ounces of fluid every 15 to 20 minutes of running. They also warn that a 2% reduction in your body weight due to fluid loss could impair performance. These recommendations were based on early studies that suggest the level of dehydration determines the body temperature response to exercise.

Heat-related illnesses can be detrimental to performance, dangerous, and potentially fatal.

Reasons People Overhydrate

Oftentimes, overhydration occurs in athletes like a long-distance runner. They are extremely prone to accidental overhydration. They don't want to get dehydrated, so they will drink extra water in order to prevent it. Dehydration will affect their performance, so they are trying to keep that from happening.

If you are an athlete, don't get carried away — it could accidentally cause you to become overhydrated.

In other cases, many dieters will drink excessive amounts of water because it takes up space in your stomach. I'm sure you've heard someone tell you to "drink water" when you say you are hungry. Fasting is a popular dietary trend that can cause overhydration if not careful.

Overhydration Diagnosis and Treatment

If you are worried about overhydration, talk to your doctor. They will go over your medical history and find out if the symptoms are caused by overhydration or another condition. Along with this, you should expect a physical examination along with other blood and urine tests.

The doctor will try to distinguish between overhydration and excess fluid in the blood by examining for signs of weight gain, edema, and testing for the concentration levels of electrolytes.

In order to treat overhydration, regardless of the cause, your doctor may restrict your fluid intake. Drinking less than a quart of fluids a day could improve your situation over the course of several days. If overhydration occurs with excess blood volume because of your heart, liver, or kidney disease, you may need to restrict sodium.

Drugs that are known to cause overhydration may be stopped, too. In some cases, doctors will prescribe diuretics to increase the excretion of water and sodium in your urine. There are also other drugs you can use to treat overhydration when your blood volume is normal.

In extreme cases, you may need to have fluids removed by dialysis or by a minor surgical procedure called paracentesis.

Preventing Overhydration

If you're an endurance athlete, you can reduce your risk of hyponatremia by weighing yourself before and after a race. This will help you determine how much water you lost and need to replenish with. Professionals recommend drinking 16 to 20 ounces of fluid for every pound lost.

While exercising, try to drink around two to four cups of fluid per hour. If you are going to be training for longer than an hour, a sports drink could be a great option. These drinks have sugar for energy, along with much-needed electrolytes like sodium and potassium, which are lost while sweating. Get in tune with your body and let thirst guide you when you need something to drink.

If you have diabetes, CHF, or kidney disease, it's best to talk to your doctor for the best treatment.

If you are unusually thirsty, it could be a sign of something serious, so go get checked out.

Professional Recommendations

Dr. Tim Noakes recently published a book Waterlogged: The Serious Problem of Overhydration in Endurance Sports. He challenges the research and findings used to develop fluid recommendations for athletes. He points to significant findings from this research that show no ill effects or impaired performance in athletes who drank little to nothing.

He argues that dehydration is simply a reduction in total body water content and the only symptom is thirst.

Oftentimes, dehydration is mistakenly blamed for heat-related illness in endurance exercise, but top elite finishers are often the most dehydrated of all runners. Overhydration, on the other hand, is a more serious condition that comes with some life-threatening complications. It can result from an athlete simply trying too hard to prevent dehydration.

Noakes mentions the signs and symptoms of hyponatremia have been described similar to that of dehydration, but Noakes goes on to state the only true symptom of dehydration is thirst.

Here are a few findings from his book:

Many of the findings from the studies on which the current recommendations were made involved "better-than-average" male athletes. A more fit athlete will be more trained and their body will be able to sustain the body temperature stresses of intense running. They will have higher sweat rates and a greater sodium loss than a less fit runner. Lastly, men generally have a higher sweat rate than women.

Noakes mentions he feels the studies fail to recognize the body's biological controls that have evolved over time. They allow our body to survive and persevere when the environmental stressors are higher.

The maximum rate that our intestines can absorb fluid is around 600 mL, or 20.3 fl oz, per hour. Your kidneys can only excrete fluid at a rate of 800 mL/hr in males, and closer to 600 mL/hr for smaller females. If you drink more fluid than this, the water will be retained and it could cause many problems associated with hyponatremia.

Noakes found that the subjects that participated in these studies had a difficult time drinking at the high rates that were required to prevent weight loss when running at such an intensity and high speed.

Noakes states that dehydration, or the reduction in body weight due to exercise, is a normal part of exercising. He states the only symptom of dehydration is thirst, to the point of the thirst being so overwhelming that you are compelled to drink when fluid is available. Studies have disproved the claim that a reduction in bodyweight of less than two percent results in impaired performance.

There is a lack of evidence to support the theory that not drinking during exercise is dangerous.

A recent meta-analysis of lab-based studies examined the impact of dehydration on performance. They found that a reduction of body weight of 2.2 percent was not associated with a decrease in performance. They also found that dehydration itself isn't responsible for any decrease in your performance, but rather not drinking in response to thirst.

The results of the meta-analysis:

"Drinking enough to satisfy thirst resulted in a 90% performance advantage when compared to drinking below thirst and a 63% performance advantage over drinking above thirst response."

This meta-analysis suggests that drinking according to your thirst is the superior hydration protocol to maximize performance.

A Little Bit About Electrolytes

Staying hydrated is more than simply replacing fluids. When we sweat, we lose important minerals that need to be replenished.

Electrolytes are minerals and they include potassium, sodium, chloride, magnesium, and calcium. We lose the most electrolytes through sweat — sodium and chloride, potassium, magnesium, and calcium — and are very closely regulated by the body to maintain many functions. Electrolytes and food, mostly carbohydrates, are responsible for facilitating the absorption of water.

They allow fluids to cross the intestinal lining into our bloodstream that can be carried to tissue in the body.

More importantly, electrolytes play a role in the regulation of your heart. They are involved in firing the electrical charges that cause muscle contractions... and your heart is one big muscle. This is what causes your muscles to cramp — your electrolyte levels are too low.

We lose most of our electrolytes through urination and sweating. The amount of electrolytes that you need to replenish your body with is based on your sweat rate. Are you someone who can run a mile without sweating? You may not need as much as someone who has flop sweat changing clothes.

Wrapping It Up

Finding the balance of how much water you need to drink can be overwhelming, but studies recommend letting your thirst levels guide you on how much you need to drink.

Previous article How Do You Test Your Gut Microbiome?