If you aren’t properly hydrated, then your body can’t perform at its optimal level. Therefore, for any athlete, whether a professional or casual competitor, staying properly hydrated is essential. Even as small as 2% dehydration can have an impact on mental and physical performance.

To get more insight on the importance of hydration, we turned to Thorne partner and professional tennis player, CoCo Vandeweghe, to learn how she stays properly hydrated on and off the tennis court.

The intensity of tennis and the importance of hydration 

In professional tennis, getting the right amount of fluids before, during, and after a match is important for performance, but also to prevent injury. Tennis is a physically demanding sport with no set times on the clock, and matches have been known to last as long as five hours.

Because tennis places a high demand on multiple muscles and joints throughout the body, it can leave even the most elite athletes feeling exhausted.

According to one study, the average tennis player has a sweat rate of 2.5 liters per hour, but it is difficult for athletes to comfortably drink more than 1.2 liters per hour during the match. 

The professional tennis season also takes place during the hot and humid months of summer, typically in warmer climates, which adds to the importance of proper hydration. So how does a professional tennis player like CoCo handle hydration?

Keeping hydrated like the pros

 “Staying hydrated for any athlete is crucial for the athlete’s success. It’s all part of taking care of the body, and for me my body is my job. I need to make sure I’m firing on all cylinders all the time. I use a variety of Thorne products to make sure my hydration levels are where they should be.”

One of her go-to Thorne products for hydration is Thorne’s Catalyte®, an electrolyte restoration complex. CoCo uses Catalyte strategically pre-, during, and post-match or training to stay hydrated.*

CoCo’s hydration routine relies on preparation, and she gets a lot of help from her team when prepping for an upcoming match.

“My team provides me with an amount that I need the night before I play, in the morning and right before. When I’m playing a match I generally drink as much as my body tells me too. During a match though, unless the points are crazy, I try to make sure I’m never thirsty,” she told us.

Before I practice, I’ll work with my trainer and make sure my drinks are prepared, and we’ll take notes on what I’m drinking to see how my body is reacting. Once we find the perfect combination, we replicate it in match play.

My advice is to take notes and listen to your body, which I tell everyone they should do anyway. You should also pay attention to the weather because it can make a huge difference in preparation and what needs to be done, especially for tennis players.”

CoCo can tell when her body is dehydrated because she notices the impact on her performance.

“Dehydration can have an awful effect on any athlete,” she said. “I’ve cramped a few times in a match when I didn’t prepare as well as I should have, and I make sure moving forward that I never make the same mistakes."

"Sometimes, due to weather and uncontrollable circumstances, dehydration can occur, but I make sure I have my Thorne products near me to counter the effects. For me personally, dehydration can be the reason I win or lose a match.”

Not just tennis stars, hydration is essential for all types of athletes 

 As CoCo notes, proper hydration is essential for every kind of athlete, no matter his or her performance level. Water regulates body temperature to keep cool, transports nutrients to aid with recovery and energy production, and helps lubricates joints. Without proper hydration, an athlete runs the risk of not only reduced performance, but also cramping and injury. Here are some healthy habits that help ensure hydration.

1. Start the day hydrated.

Just as CoCo plans out her hydration needs, plan to start your day hydrated. Drink 16 ounces of water as soon as you wake up for optimal hydration. Track your morning body weight in the summer months for water weight fluctuations, and look for the classic signs of dehydration, such as cracked lips, dry skin, or dry mouth.

2. Determine your sweat rate.

An individual’s sweat rate is the amount of fluid they lose in sweat during a workout. A simple formula to roughly calculate sweat rate is:

Sweat rate loss in ounces per hour = [(Body weight before exercise or activity minus body weight after exercise or activity) plus the amount of fluid in ounces consumed during exercise or activity] divided by the duration of the exercise or activity.

Knowing your sweat rate determines how much fluid you should ideally consume during exercise or activity to stay hydrated. For a 150-pound person, as little as three pounds of sweat loss (equivalent to three pints of water) can impact mental and physical performance.

3. Keep a water bottle with you.

Another easy hydration habit is to take a water bottle with you wherever you go, such as the car, the office, and your daily commute. This will remind you of your daily hydration needs. You should need to urinate regularly throughout the day, and your urine should be a light lemonade color.

4. Avoid sugary sports drinks.

Beverages traditionally advertised as sports drinks are too low in electrolytes to cover typical sweat rates. In addition, many sports drinks have a high sugar content or artificial sweeteners.

Thorne’s Catalyte is a low-sugar electrolyte powder and is formulated based on the typical ratio of sodium found in sweat, and it also includes a blend of potassium, calcium, magnesium, and zinc – which are also lost in sweat, but rarely included in sports drinks. See how it stacks up to other sports drinks.

5. Watch for signs of dehydration during exercise. 

Knowing the signs of dehydration during exercise will help to avoid it. Common signs of dehydration include a decline in coordination, decrease in energy, reduction in athletic performance, muscle fatigue, muscle cramping, and dizziness.

Thorne’s mission is to help individuals discover and achieve their best health. See how Thorne employees, partners, athletes, and everyday individuals use Thorne products to optimize their health. This article is part of Thorne’s #MyThorneStory series, an ongoing series that documents the stories of Thorne employees and Thorne enthusiasts as they pursue their passions.


1. Kovacs M. Hydration and temperature in tennis - a practical review. J Sports Sci Med 2006;5(1):1–9.