5 Hydration Mistakes That Make a Workout Harder

March 29, 2015

by Cathe Friedrich

Two factors that can greatly impact your exercise performance: low glycogen stores and inadequate fluid intake. Your body is made of 60% water and your brain is between 75% and 85% water. No wonder even mild dehydration negatively affects mood AND athletic performance. If you’re feeling fatigued, weak, lightheaded, dizzy when you bend over or get up off the exercise mat, you’re likely dehydrated, but mild dehydration can cause subtler symptoms like lack of motivation and reduced performance. It’s important to get the hydration thing right – but not everyone does. Here are some of the most common hydration mistakes.

Counting on Thirst as an Indicator of when to Drink

When you need fluid, your body will let you know, right? It will, but only after you’re already mildly dehydrated. Your body usually doesn’t send you a strong thirst signal until you’re around 2% dehydrated. This degree of dehydration is enough to negatively impact your exercise performance and make a workout feel harder. Plus, you’re more likely to get a painful muscle cramp when your fluid and electrolytes are out of balance. Don’t forget, you also need water for adequate joint lubrication.

The key is to not reach the point that you’re thirsty, because once you do you’re already too far behind and will have problems “catching up.” Dehydration decreases fluid volume in your blood vessels, and your heart has to work harder to pump blood and oxygen to tissues. Your brain is also hit hard by lack of fluids and you may experience decreased motivation, excessive fatigue, lightheadedness or dizziness.

Not Monitoring Your Fluid Intake

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

If you’re working out in a very warm environment, are pregnant or taking certain medications, like diuretics, you may need to drink even more fluids. There are two ways to determine whether you’re meeting your body’s fluid requirements: weigh before and after your workout and by monitoring the color of your urine.

To use the weight method, weigh yourself before exercising and again when you finish. If your weight has dropped more than 2 pounds, you’re not drinking enough fluids before and during your workout. Once you know how much your weight has fallen, drink 2.5 glasses of water for every pound lost to replenish your body’s fluid stores.

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

Assuming Water is Good Enough in Every Hydration Situation

For exercise lasting less than 90 minutes in a relatively cool environment, water is sufficient as a hydration beverage. This isn’t necessarily true with longer periods of exercise or when you’re 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 dilute out the sodium in your bloodstream and tissues even more.

When sodium falls too low, you can experience confusion, lightheadedness, dizziness, fluid retention and even death. When exercising in a hot environment or doing a long workout, switch to an electrolyte-rich beverage. Coconut water is an alternative to sports drinks, although it’s a bit low in sodium. You can increase the sodium content by adding salt. Whatever beverage you’re consuming should contain at least 100 milligrams of sodium per 8-ounce serving.

Not Knowing When a Sports Drink is Appropriate

You generally don’t need a sports drinks for workouts less than 90 minutes in duration As long as your glycogen stores aren’t low at the beginning of your workout, you don’t need the added carbs that a sports drink offers. If you’re exercising for more than 90 minutes or competing in an event like a marathon, you’ll benefit from the extra carbs a sport drink offers. Unfortunately, many sports drinks contain artificial flavorings and colorings. Why not make your own?

Drinking Bottled Water

Despite the convenience and public perception, bottled water isn’t necessarily better for you. When an independent firm, Environmental Working Group, tested a variety of bottled waters, they found contaminants in most brands they tested, including chemical by-products and even medications. Some bottled water makers are essentially bottling tap water and asking you to pay for it.

Plus, plastic bottles that hold the water are made with plasticizers that leech into the water. Experts are worried about the health effects of plasticizers, especially BPA. Until more is known, it’s best to avoid drinking out of any type of plastic container. If you’re concerned about the quality or taste of the tap water in your home, buy a water filter. Then invest in a stainless steel water bottle you can use to carry water around with you.

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 the guidelines for staying hydrated and monitor your fluid status after your workouts by weighing or checking the color of your urine. Some people sweat more profusely during exercise than others. By monitoring your hydration status, you’ll get a better feel for how much fluid you need to stay properly hydrated.

References:

Coach and Athletic Direction. “Five Hydration Mistakes and How to Correct Them” July/August 2014.

WebMD. “Rethinking Bottled Water” June 19,2013.

WebMD. “Water Tips for Efficient Exercise” July 2009.