You do everything possible to ensure your horse stays well hydrated throughout the summer, but are you paying close enough attention to your own fluid intake when the weather heats up? Unlike some sports that primarily require cardiovascular fitness, you need both endurance and immense muscle strength to pilot a 1,200-pound animal through a dressage test. And because our muscles are 70% water, proper hydration is of particular importance to equestrian athletes.

Additionally, riders’ traditional show wardrobes (breeches, tall boots, multiple top layers, gloves and helmet) aren’t exactly heat friendly and often result in greater fluid loss from sweat. And while there are indoor showing opportunities in some parts of the country throughout the summer, many equestrians don’t have that option and therefore have to learn how to cope with the heat.

Water is our body’s most important element and is more necessary than food. Emily Cooper, MD, and medical director of Seattle Performance Medicine, says that water intake affects our athletic performance in so many ways that paying attention to how you hydrate is essential. Here, we’ll help you determine how much H20 you should be drinking when riding in the heat, provide dehydration warning signs and offer tips on how to boost your water intake.

Liquid Gold: Why Water Is Essential For Performance

Water is essential to every body system, but here are a few it its key jobs:

• Water delivers oxygen to muscles and carries waste products away
• It helps maintain blood pressure. “Imagine your veins are pipes and your heart is a pump,” Cooper said. “Without enough fluid, the heart has to work harder to deliver blood throughout your body.”
• Water carries moisture to skin and eyes and lubricates our joints.
• It transmits heat produced by working muscles to the skin through circulation to produce sweat, which helps keep our core temperature stable and essentially enables the body’s cooling function that’s crucial during athletic activity.

While thirst is one of the body’s ways of letting you know you need more fluid, Cooper says that if you wait until you’re thirsty, you’re already behind. You’ve probably heard the eight-glasses-a-day advice, but a person’s water needs are highly individualized and depend on multiple factors. For a very general rule of thumb on your fluid needs when you’re not exercising or outside in hot weather, simply divide your body weight (in pounds) in half for the number of fluid ounces you need per day.

When you exert yourself through exercise, especially in hot, humid weather, your water needs can significantly increase depending on how much you sweat. Sweating can also vary from person to person, but a typical sweat rate is about 20 to 40 ounces for every hour, indicating how much water you would need to replace what you lost through sweat, in addition to your baseline needs in non-exercising circumstances.

It might be tempting to combat this by pre-hydrating with the amount of sweat you expect to lose before your ride, but unfortunately Cooper says that doesn’t work. The most effective strategy is to start your show day properly hydrated and then maintain that hydration by drinking enough fluid either during or after exertion to replace what you lose through sweat. Additionally, if you’re exercising and sweating a lot, you’ll need to continue to hydrate for the rest of the day even when you’re back indoors.

Signs You’re Not Drinking Enough Water

Thirst: By the time you’re aware of this first dehydration indicator, you’re already about a liter of fluid behind what you need.

Headache and dizziness: Dehydration reduces blood flow to the brain, which can result in headache, dizziness or confusion—you might even feel like you’re going to pass out.

Fatigue and muscle cramps: These occur when large muscle groups are deprived of oxygen and waste products aren’t removed.

Soreness: Muscles won’t recover well after exercising if you’re not well hydrated and you may experience prolonged muscle soreness.

Reduced performance: In severe cases of dehydration, muscles will actually break down and release large amounts of waste products, which can overload the kidneys and even lead to kidney failure.

Symptoms of Dehydration

When your body experiences inadequate water intake, it can lead to dehydration, heat exhaustion or heatstroke, which can be fatal.

• Dry mouth
• Sunken eyes
• Deep, rapid breathing
• Dry, wrinkled skin
• High heart rate, but low blood pressure
• Flushed skin
• Loss of appetite
• Heat intolerance or chills
• Dark-colored urine

Drink Up: How To Stay Hydrated in the Saddle This Summer

August of 2024 was the hottest month ever recorded, according to both NASA and the National Oceanic and Atmospheric Administration—and higher than average temperatures are predicted for much of the U.S. this year. High heat along with high humidity poses the most dangerous dehydration risk. As sweat evaporates, it helps remove heat from the body. When the air is moist, that cooling mechanism is less efficient. Overcast and humid conditions can sometimes be worse than direct sunlight in drier climates.

When the weather heats up, it’s crucial that you pay close attention to your fluid intake. Follow these strategies to ensure you’re hydrating right:

Drink clear fluids: Unconcentrated, clear fluids are key to proper hydration. Cooper notes to avoid juice and milk, and opt for water, herbal teas and some sports drinks. “It’s important to be aware of the difference between sports waters and sports drinks. The waters have added flavoring only,” she said. “Sports drinks often contain sodium and other electrolytes like potassium, magnesium and calcium to replace key minerals lost through sweat and can be good option when exercising in hot weather, in addition to plenty of water.” Avoid sports drinks with added sugars.

Limit caffeinated beverages: Caffeinated drinks can have a diuretic effect, but only in the absence of exercise. “Once you start exercising,” Cooper explains, “the diuretic effects are blocked.” Caffeinated or not, she advises against soda for hydration.

Up your fruit and veggie intake: The water content of fruits, vegetables and brothy soups also can help boost your overall hydration.

Opt for cool drinks: Cold fluids empty out of the stomach and into your system faster than warm beverages.

Gulp: When exercising in hot weather, gulping is better than sipping; having more fluid entering your stomach at once, rather than in small amounts, also aids gastric emptying.

Avoid alcohol: While your horse might benefit from a stout beer on hot show days if he struggles with anhidrosis, skip that glass of wine the night before competition as alcohol leaves you dehydrated.

Replace salt: Other than water, salt is the biggest substance that we lose on a hot day and is also vital to replace. Cooper says that when sweating on hot days, people generally need around 300 to 600 mg (or 1/16 to 1/8 teaspoon) of salt per hour. Signs that your salt is low include subtle calf cramps, frequent urination or puffiness in the fingers or toes. You also might notice white caking on your skin or sweaty clothing, similar to the salt residue you see on your horse’s coat after he’s been sweating heavily. To ensure, you replace salt lost through sweat, she recommends drinks with sodium and other electrolytes (salt, along with potassium, magnesium and calcium, is an electrolyte) or salty snacks.

Monitor your calcium, magnesium and potassium needs: If you’re going to be exercising and sweating for more than six hours, your muscles will use more calcium and magnesium through repetitive contractions. In hot weather, you’ll also lose potassium through sweat. Though unlikely for most equestrians, endurance riders or eventers who ride multiple horses in a competition, can experience painful repetitive muscle contractions, which can be serious and even require prompt medical attention. Cooper recommends supplementing with 250 mg of calcium and magnesium every four hours during long events when muscles are working continuously. Many sports drinks contain calcium, magnesium and potassium, or try snacking on foods high in potassium like bananas, kiwis or energy bars.

For More:

• For more tips on riding in the heat, click here.
• For advice on how to ensure your horse stays well hydrated throughout the summer, click here.
• The Heat Index (a measure that combines air temperature and relative humidity to estimate how hot it actually feels) also plays a big role when trying to hydrate before riding in the heat. You can the find the National Weather Service heat-index calculator here.