6 Hydration Mistakes You Are Making During Exercise

6 Hydration Mistakes You Are Making During Exercise

Two factors can have a major impact on exercise performance: low glycogen stores and insufficient fluid intake. Your body is made up of 60% water and your brain is made up of 75% to 85% water. Not surprisingly, even mild dehydration negatively impacts mood AND athletic performance.

If you feel tired, weak, light-headed, or dizzy when getting up or off the exercise mat, you’re probably dehydrated, but mild dehydration can cause more subtle symptoms like lack of motivation and a drop in performance. It’s important to stay hydrated, but not everyone does it. These are some of the most common drinking mistakes.

What Does Hydration Mean

The amount of water you need depends on several factors such as the weather conditions, your health, your clothing, and the intensity and duration of the training. Therefore, staying well hydrated varies from person to situation. 

As a guide, you may need more fluids if: 

  • You sweat a lot 
  • You have certain medical conditions such as diabetes or heart disease 
  • You have cystic fibrosis, which means you have high levels of sodium in your sweat 
  • You are taking a drug known as a diuretic, causing your body to lose more fluids in hot or humid conditions. 

Thirst is not the best indicator that you need to drink. If you’re feeling thirsty, you’re probably already dehydrated. A good test for dehydration is the colour of the urine. If it is pale and clear, it means you are well hydrated. The darker it is, the more liquid you need to drink. 

Another sign of dehydration is the lack of sweating during vigorous activity when sweating is expected. Not sweating is a sign that you are dehydrated and likely suffering from heat exhaustion.

Sweat and Dehydration

When you exercise, your body sweats as it tries to return to its optimal temperature. When sweat evaporates from the skin, it removes heat from the body, but bodily fluids are also lost.

Therefore, you need to drink fluids during exercise to replace the fluids you lose through sweating. This way you reduce the risk of heat stress, preserve normal body function, and maintain performance levels. The rule of thumb is: If you sweat, you should drink fluids. It’s possible to drink too much while exercising. Overhydrating can cause death in rare but severe cases. To avoid over-or under-hydration, it can be helpful to know your sweat rate. This way you can find out exactly how much to drink.

Count On Thirst as an Indicator of When to Drink

When you need hydration, your body will let you know, right? It will, but only after you’re already slightly dehydrated. Your body doesn’t usually send you a strong thirst signal until you’re about 2 hydrated. This level of dehydration is enough to negatively impact your exercise performance and make exercise more difficult. Also, you’re more likely to get a painful muscle spasm when your fluids and electrolytes are out of balance. Don’t forget that you also need water to properly lubricate the joints.

The key is not to get to the point where you are thirsty because if you do you will be far behind and have trouble “catching up”. Dehydration reduces the volume of fluid in the blood vessels and the heart must work harder to pump blood and oxygen to the tissues. Your brain is also severely affected by dehydration, and you may experience decreased motivation, excessive tiredness, light-headedness, or dizziness.

Not Monitoring Your Fluid Intake

How do you know if you’re drinking enough fluids? In general, you should drink 15 to 20 ounces of water an hour before your workout and another glass within 30 minutes of your workout. The hydration guidelines mentioned are for the average person.

If you exercise in a very hot environment, are pregnant, or take certain medications such as diuretics, you may need to drink even more fluids. There are two ways to tell if you’re getting your body’s fluid needs: Weigh yourself before and after your workout and check the colour of your urine. To use the weight method, weigh yourself before your workout and weigh yourself again when you’re done. If your weight has dropped more than 2 pounds, you’re not drinking enough fluids before and during exercise. Once you know how much weight you’ve lost, drink 2.5 glasses of water for every pound lost to replenish your body’s fluid stores.

Urine colour is also a reasonable indicator of hydration status. If you drink enough fluids, your urine should be pale yellow to clear. If it’s darker, you’re suffering from some degree of dehydration.

Assuming That Water Is Good Enough in Any Drinking Situation

For an exercise lasting less than 90 minutes in a relatively cool environment, drinking water is sufficient. This is not necessarily true for longer periods of exercise or when exercising in a hot environment. When you sweat, you lose water and sodium. If you lose a significant amount of sodium and rehydrate with water, you will further dilute the sodium in your bloodstream and tissues.

If your sodium levels drop too low, you can experience confusion, light-headedness, dizziness, fluid retention, and even death. If you’re exercising in a hot environment or doing a long workout, switch to an electrolyte-rich drink. Coconut water is an alternative to sports drinks, although it’s somewhat low in sodium. You can increase the sodium content by adding salt. Each beverage you consume should have at least 100 milligrams of sodium per 8-ounce serving.

Not Knowing When a Sports Drink Is Appropriate

For workouts shorter than 90 minutes, you generally don’t need a sports drink. If your glycogen stores aren’t low when you start your workout, you don’t need the extra carbs a sports drink offers. If you’re exercising longer than 90 minutes or participating in an event like a marathon, you’ll benefit from the extra carbohydrates that a sports drink provides. Unfortunately, many sports drinks contain artificial flavours and colours. Why not do it yourself?

Reasons for Insufficient Hydration

1. Not Hydrating Before Exercise

When we exercise, we sweat and lose water. To counteract this, we drink during training. But if you don’t hydrate before you exercise, you’re hydrating poorly.

Not drinking before exercise can cause headaches. You put yourself at risk of becoming dehydrated as you lose more water than you have in your system. Be sure to drink at least 30 minutes before exercising.

2. Avoid Coffee or Tea

You probably know that if you drink coffee or tea, you go to the bathroom more often. These drinks are known as diuretics and for this reason, people may avoid them believing they are losing water. You lose fluids when you urinate, but coffee and tea still contain water to keep you hydrated, so you don’t have to skip them.

3. Drink Rarely

When we’re thirsty we drink, or when we exercise, we drink, but you don’t have to answer your body’s call to stay hydrated. Even if you’re sitting on the couch or at your desk, it’s important to stay hydrated.

Staying hydrated keeps us awake. When you are at work, drinking water is a good habit as it can keep you awake, energized, and active throughout the day.

4. Drink Only 8 Glasses a Day

We are taught again and again to drink 8 glasses a day. New research from the Institute of Medicine recommends 11.4 cups a day, but even that guideline varies from person to person. Instead of trying to follow a general rule, go with your body. Individuals of different ages, activity levels, and sizes require different amounts of hydration. While eight glasses a day is a good start, feel free to expand to suit your personal needs.

5. Drinking Too Much, Too Fast

Drinking too much water again too quickly is not a good choice since the stomach can only process two to four ounces every half hour. Also, the kidneys can only filter 27 to 33 ounces of water per hour. Doing this in excess can lead to stomach pain and cell inflammation. Instead, drink plenty of water regularly.

6. Drinking Cold Water

Drinking super cold water can stimulate the vagus nerve to go into shock, which can cause you to pass out. Also, super cold water constricts blood vessels, which can make it harder to stay hydrated.

What to Drink

There are other ways to rehydrate than plain water. Some are only suitable for longer and more intense races.

Cold Water

Drinking cold water helps cool the body and slows sweating (and associated water loss). Research shows that drinking cold water, or even an ice-cold slushie, can improve and extend your mileage.Also, most people prefer the taste of cold water, allowing them to drink more water when it’s cold.

Sports Drinks

If you run longer than 90 minutes, especially if you sweat, you should start using an electrolyte-replacing sports drink. Depending on the conditions, you can alternate it with water or just switch to sports drinks at this time.

Sports drinks like Gatorade or Powerade contain electrolytes like sodium and potassium, the components of table salt. When you run, your body loses electrolytes through sweat. You’ve probably already seen the salt stains on your running hat and tasted the salt in the sweat that ran down your cheeks.

Since electrolytes help your body retain fluid and prevent muscle cramps, you should replace them. After 90 minutes, you also need to consume more carbohydrate calories to sustain your effort, so a sports drink that provides carbohydrates and electrolytes is helpful.

Some runners find that it is sometimes easier to get their calories from liquids than from solid foods, particularly in the latter stages of a race or long run. If you don’t mind the taste (or sugar content) of commercial sports drinks, you can make your own.

Runners who do not adequately replenish electrolytes during long runs or races may be at risk of overhydration. Hyponatremia, a low level of sodium in the blood, can occur when athletes drink excessive amounts of water and don’t replace the salt lost through sweat.

Flavored Water

If you don’t like the taste of plain water (even if it’s ice-cold), you can flavour the water to make it more appealing, so you drink enough. Some water additives also contain electrolytes, but many do not. Be careful if you walk an hour or more, especially on a hot day. You may need a sports drink in addition to flavoured water.

Coconut Water

Some runners enjoy drinking coconut water or using it as a recovery drink. It contains calories from carbohydrates and some electrolyte micronutrients, including potassium and magnesium. It also contains natural sugars that could provide an energy boost. However, it does not contain as much sodium as sports drinks.


Some research shows that consuming caffeine before a race or long training run can improve performance and endurance. If you depend on coffee in the morning, it’s okay to have some before an early run.

Caffeine is a diuretic, meaning it can increase the urge to urinate. Keep that in mind when going to the toilet while running. Caffeine doesn’t increase your risk of dehydration, so you don’t need to worry about that. While not everyone can tolerate coffee or other caffeinated beverages before a run (it can cause an upset stomach), it’s okay to drink when you can.

Carbonated Drinks

Carbonation in soft drinks can also upset your stomach, leading to bloating and bloating. It’s generally not a good idea before or during a race. The sugar in non-diet soda can promote weight gain. If you drink soda, don’t drink water or any other healthier beverage. But at endurance events like marathons, some runners like a little coke to give them an energy boost (over sugar and caffeine).

The Bottom Line

Are You Hydrating Well Enough? If not, you may not be performing as well as you could. Don’t use thirst as a guide. Follow guidelines to stay hydrated and monitor your post-workout fluid status by weighing or checking the colour of your urine. Some people sweat more than others when they exercise. By monitoring your hydration status, you can get a better idea of ​​how much fluid you need to stay well hydrated.


Saravavan Nadarajan (Vanan)

Vanan, fitness expert and leader at EzFit Singapore, specializes in holistic training—home-based, boot camps, and corporate fitness—with over a decade of industry experience.

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