If you don’t drink enough fluids before, during, and after exercise, particularly when you’re sweating a lot, you could become dehydrated. Dehydration “plays a huge role in mental and physical health,” says Jamie Hickey, a NASM-certified personal trainer and registered dietitian at Truism Fitness in Philadelphia. When you’re dehydrated, “everything in your body, from your muscles to your cells to your cognitive function, is affected,” he says, adding that dehydration can also cause fatigue and dampen your motivation. Marni Sumbal, RDN, a sports dietitian based in Greenville, South Carolina, adds that being properly hydrated helps optimize exercise performance. “It can help the blood pump more efficiently and it can help with cooling your body,” she says. “It can help with perceived exertion, so it can make you feel better.” The exact amount you need to drink will vary depending on the temperature, humidity, and your exertion level, per the Mayo Clinic. But one of the easiest ways to monitor your hydration is to keep an eye on the color of your pee, Hickey says. When you’re well hydrated, your urine will be a pale yellow, like the color of wheat. When you’re dehydrated, it will be darker. You’ll also pee less frequently when you haven’t had enough to drink. Other signs of dehydration include extreme thirst, dizziness, and confusion, according to the Mayo Clinic. Read on to learn the most common exercise hydration mistakes you should watch out for.
1. You Don’t Drink Enough Before, During, and After Exercise
Sumbal advises most people to drink 17–20 ounces (oz) of water in the two hours before exercise, in addition to 8 oz about 20 to 30 minutes before they start working out. During your workout, aim to drink another 8 oz of water every 10 to 15 minutes. Afterward, drink 12 to 24 oz of water. The more you sweated during your exercise session, the more fluids you’ll need to replace, Sumbal says.
2. You Don’t Plan How You’ll Hydrate
If you’re taking a long walk, jogging, running, or swimming, you may forget to keep water handy or you may not feel like bringing a bottle along. But relying on water fountains to keep you hydrated is a mistake, Sumbal says. “Most of the time, what ends up happening is people get dehydrated and then they end up guzzling water after [their exercise session], and by then it’s too late,” she says. Instead, plan exactly how you’ll stay hydrated during your workout, and figure out a system for carrying water or a sports drink with you. For example, some people like to use fanny packs or carry a light backpack. Runners may choose to use a handheld water bottle. If you’re cycling and have a water bottle holder on your bike, make use of it, but remember to clean and refill your bottle between workouts.
3. You Don’t Replenish Lost Electrolytes
The average person will lose up to half a liter of sweat every 30 minutes while exercising, Hickey says. This figure can rise to between three and four liters of sweat per hour, depending on metabolic rate, according to past research. Sweat primarily consists of water, but it also includes important electrolytes, notes Ace Fitness: sodium, chloride, potassium, magnesium, and calcium. Electrolytes are minerals in the body found in bodily fluids such as blood and urine, per MedlinePlus. They help manage a number of bodily functions, including nutrient absorption, waste removal, and water distribution in the body. Sweating, vomiting, and diarrhea can all lead you to lose electrolytes, leaving you feeling dehydrated or causing muscle cramps and spasms, as the Cleveland Clinic notes. Sodium is the electrolyte your body loses in the biggest quantities when you sweat — so “if you’re sweating a lot, you need to replenish your salt intake to help yourself stay hydrated,” Hickey says. People who work out intensely for about an hour, or exercise in the heat, ought to consume a sports drink to help replenish electrolytes, Sumbal says. But it’s important to think carefully about which one, or you could be risking another hydration mistake.
4. You Don’t Choose the Right Sports Drink
One of the keys to replenishing lost electrolytes is choosing your sports drink wisely. Many sports drinks, such as Gatorade and Pedialyte, are specifically designed to maintain your body’s electrolyte balance when you’re sweating a lot. You can also find electrolyte powder or tablets, which you can mix into a bottle of water, at many drugstores. Coconut water replenishes lost electrolytes such as potassium, sodium, and manganese, according to Mayo Clinic (but check the label to confirm the electrolyte content, which varies by brand). Many people choose sugar-free, calorie-free, or low-sodium sports drinks, which are commonly available at the grocery store. “But a sports drink should supply you with carbohydrates and sodium, so you really want to make sure those things are in the drink,” Sumbal says. “If you’re consuming a sports drink, there’s a purpose for that.” Avoid highly caffeinated, high-sugar energy drinks such as Red Bull and Monster, which can lead to increased blood pressure, irritability, restlessness, and a higher risk of dehydration, according to past research. And keep in mind that adults and children alike should opt for sports drinks over water only during strenuous exercise that lasts for over an hour, per UnityPoint Health.
5. You Don’t Get Enough Magnesium
As an electrolyte, magnesium helps restore hydration status during recovery, notes Caroline Thomason, RDN, CDCES, a nutrition coach based in Northern Virginia. But many people don’t meet their recommended magnesium intake, especially men over 70 and teens, according to the National Institutes of Health Office of Dietary Supplements. In this case, consider adding more magnesium-rich foods to your diet — opt for legumes, nuts, seeds, whole grains, leafy greens, milk, and yogurt. Fortified foods, like fortified cereals, can also help you boost your magnesium intake. Magnesium supplements may carry some benefits for your workout, too. If you’re struggling with leg cramps or muscle pains, using a magnesium powder can help muscles relax, Thomason advises. (Research published in Scientifica in 2017 found that, while magnesium may help mildly improve leg cramps, further studies are needed to confirm the effect.) Bonus: Other research, published in Nutrients in 2017, has suggested that magnesium supplements could help enhance exercise performance, including grip strength and lower-leg power. But more research is necessary to confirm these potential effects. You can find magnesium powder at many drugstores; mix it into water and drink it hot or cold. You can also find magnesium in many multivitamin-mineral supplements and other dietary supplements. Keep in mind, though, that the upper recommendation for magnesium taken via supplements is 350 milligrams (mg) per day for adults and children ages 9 to 18, per the National Institutes of Health Office of Dietary Supplements. Exceeding this amount can cause diarrhea, nausea, and abdominal cramping; extremely high intake can cause irregular heartbeat and even cardiac arrest. Magnesium supplements can also interact with some medicines, including bisphosphonates, antibiotics, diuretics, acid reflux and peptic ulcer drugs, and zinc supplements. Talk to your doctor if you are considering taking a magnesium supplement, especially if you take any of these medications.
6. You Drink Alcohol After a Workout
Maybe you like to unwind at the end of the day by cracking open a cold one. But if your happy hour follows a workout, think again. Drinking alcohol after exercise is a mistake, Sumbal says: “Alcohol is not a rehydrating beverage. It doesn’t contain the right nutritional profile to act as a recovery beverage.” Indeed, alcohol contributes to dehydration, notes the Cleveland Clinic. Skip the booze after your workout session; instead, Sumbal suggests opting for a glass of water, a sports drink, or even some milk. As noted above, coconut water or electrolyte mixes are good options for a post-workout beverage.
