Do You Know the Truth Behind These Hydration Myths?

ISSA, International Sports Sciences Association, Certified Personal Trainer, ISSAonline, Do You Know the Truth Behind These Hydration Myths?

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Staying hydrating, rehydrating after a workout, and avoiding dehydration are all important for optimal performance and health. Unfortunately, there are a lot of myths surrounding hydration. 

Most of these myths are minor issues, but some can be dangerous. Be sure your clients understand how to hydrate correctly and how to distinguish fact from fiction. 

The Importance of Hydration

Maintaining an adequate amount of fluid in the body is essential for good health. It is essential for life too, as all the functions of the body occur in water. Proper hydration is necessary for many, many things. These are just a few of the most important: 

  • Temperature regulation
  • Lubrication of joints
  • Delivering nutrients to cells
  • Preventing infection
  • Removing waste from the body
  • Normal functioning of organs

What is Dehydration? 

The definition of dehydration is when the body loses more fluid than it takes in, to the extent that it cannot function normally. A little bit of an imbalance in fluids can be corrected easily. If you do not correct it and the imbalance widens, you can become dehydrated. 

Most people don’t get dehydrated on a typical day. Illness that triggers vomiting or diarrhea is a common cause of dehydration. You may also become dehydrated from sweating excessively—through physical activity, high temperatures, or both—and not rehydrating. Some people are more vulnerable to dehydration, including older adults. 

An important component of hydration is electrolyte balance. Check out this ISSA post to learn more about electrolytes and how to include them in your hydration strategy. 

Understanding Hydration Myths and the Dangers of Dehydration

As a trainer and a fitness enthusiast, you have more reason than others to take an interest in hydration. Dehydration can be dangerous, even life-threatening, so it’s necessary to understand the myths circulating about hydration. Dehydration can cause: 

  • Severe thirst
  • Limited urination and dark-colored urine
  • Dizziness
  • Confusion
  • Fatigue

If not corrected, dehydration can cause more serious complications: heat exhaustion, heat stroke, urinary tract infections, kidney failure, seizures, and hypovolemic shock. The latter can be fatal. 

Top Hydration Myths, And the Actual Truth

Hydration is important. Even mild, non-life-threatening dehydration can cause uncomfortable symptoms. It can give you headaches, impact your sleep, and diminish athletic performance. For you, and for your clients, know the myths and the truths about staying hydrated. 

Myth #1 – Everyone Needs to Drink Eight Glasses of Water Per Day

It’s not a bad guideline, but the eight glasses rule is too general. It comes from a recommendation made by the U.S. Food and Nutrition Board in 1945, so needless to say it may be a little out of date. The recommendation was that everyone consume 2.5 liters of water per day. This was not based on any research. It also suggested the total amount could come from food. You can get a lot of water from foods, especially if your diet is high in fresh fruits and vegetables. Other drinks also provide water.

Current researchers have found that it simply isn’t possible to determine an average water requirement because everyone is different. Situations also vary. You need to drink more or less water depending on your activity level, the temperature, and what you’re eating throughout the day. 

Myth #2 – Drinking More Water Flushes Toxins and Supports the Kidneys

Many people believe that more water is always better. It’s true up to a point. If you consume enough water to stay hydrated, any more is unnecessary. Excess water will not help your kidneys flush more toxins out of your body. They do this around the clock, no matter how much extra water you consume. 

A recent study proved this using participants with kidney disease. One group in the study continued their normal hydration habits, while another group was directed to drink more. Those who drank more water had no improvements in kidney function compared to the others. 

Myth #3 – Drinking Too Much Water is Impossible

This is a dangerous myth. Not only can you drink too much water, but it can be deadly. Excess water intake can lead to low sodium in the blood, a rare condition called hyponatremia. Symptoms include nausea, vomiting, headaches, confusion, fatigue, drowsiness, muscle weakness and cramps, irritability, and restlessness. Ultimately it can cause seizures and coma. 

Certain medical conditions can cause hyponatremia, but it sometimes also occurs in athletes trying too hard to hydrate. A tragic story pops up in the news every few years about marathoners drinking too much water and dying from hyponatremia. It is rare but a real and dangerous risk. 

Myth #4 – Caffeine is Dehydrating

There is a small amount of truth to this statement. Caffeinated drinks can act as diuretics, increasing urine output, but not by as much as you think. A study compared people who consumed the same amount of fluids daily. One group only drank water, while the other drank tea and coffee. Both groups had similar hydration levels. 

A significant diuretic effect of caffeine only kicks in at about 300 milligrams per day or more. This is the equivalent of three or more cups of coffee and six or more cups of tea. Exercise also seems to counteract the diuretic effect, possibly because blood flow is moving to the muscles, bringing less fluid to the kidneys. 

Does coffee promote fat metabolism? Find out here

Myth #5 – If You’re Thirsty, You’re Already Dehydrated

Thirst is a great indicator of fluid needs, but it doesn’t necessarily mean you are dehydrated. The initial feeling of thirst should urge you to get a drink. Ignore it for too long, especially if you’re working out or sweating from hot temperatures, and you soon will be dehydrated. 

Myth #6 – Water—Or Sports Drinks—Are Always Best

Neither one is always the best option for hydrating. Choose your drink based on the situation. For a typical day without too much activity or sweating, water is perfectly fine. Even other drinks, like tea or juice, along with water from food, are enough to keep you hydrated. 

A sports drink, which contains electrolytes and some carbs, is particularly useful for quicker hydration. The sugar and sodium in these drinks help your body absorb it faster. Use sports drinks for competitions, difficult workouts, or if you work outside on hot days. 

Myth #7 – Drinking Water Will Help You Lose Weight

This is another one that is mostly myth with an element of truth. Drinking extra water in itself does nothing to promote weight loss. One myth about this, for instance, is that drinking more water forces the body’s metabolism to rev up in order to maintain temperature. 

The truth is that drinking more water can help you control your appetite to some extent, and that in turn can support your weight goals. Just don’t expect water to be a miracle weight loss tool. Try drinking a big glass of water before a meal to eat less. 

Hydration is essential for everyone, but even more important for active people and athletes. Keep your clients informed about hydration and help them make the best choices. 

The ISSA’s Nutritionist program includes information on both food and hydration strategies. The course gives you everything you need to start a career as a nutrition coach or to add the service to your personal training business. 


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