Higher Education

South Florida Professor Provides Expert Stance on Hydration


Higher Education

South Florida Professor Provides Expert Stance on Hydration

Tim Carey collapsed during a race because he drank too little water. He threw up during another race because he drank too much of it. Through trial and error, the Dallas runner seems to have found his Goldilocks amount.

“My secret now,” says Carey, 44, “is however much water I think I need, I’ll take a third of that away.”

For him, the net amount is one to two gallons a day. Emphasis on “for him.”

“Hydration is difficult because not everybody has the same fluid needs,” says Rebecca Lopez, an assistant professor and athletic trainer in the Morsani College of Medicine at the University of South Florida. She co-wrote the 2015 National Athletic Trainers’ Association position statement on exertional heat illnesses.

“It depends on the individual and the environment they’re in,” she says. “Too much water is bad, and too little water is bad as well. You want to be equally fearful of both.”

Even among people doing the exact same workout or race, the need varies depending on how much they sweat, how much they weigh, how long they’re exercising and what the overall environment is.

Plus — and perhaps especially in Texas and the South because of often higher temperatures and humidity — people tend to fear dehydration so they sometimes overcompensate. When that happens to the extreme, it’s called hyponatremia and, though rare, can be deadly.

“The idea of exercise-induced hyponatremia was first in marathon runners and ultra athletes,” says Dr. John Pease, chief of emergency services at Parkland Memorial Hospital and assistant professor of emergency medicine at UT Southwestern Medical Center at Dallas. “But now it’s more in high school and college. In the hot Texas sun, and with sports doing double sessions, coaches often encourage athletes to drink and drink and drink.”

In August 2014, a high school athlete in Georgia tried to ease his workout-induced cramps by drinking gallons and gallons of water and Gatorade. He slipped into a coma and died.

What’s tragic about his death and others, Pease says, is that “they probably could be prevented by letting the body dictate how much we drink.”

“These myths get propagated that you want to stay ahead of the curve” when it comes to drinking enough water, he says. “You want to stay hydrated, but don’t want to overdo it. It’s more dangerous to be overhydrated.”

Being a little dehydrated is “no big deal,” says Meridan Zerner, registered dietitian at the Cooper Clinic. “I’d love for people to be hydrated because the brain is 70 percent water. There is a link between being hydrated and cognitive performance.”

“We don’t have to drink volumes and volumes and volumes. It can be four ounces here and four ounces there. We know there’s not a magic number.”

So what’s the best way to figure out how much water you need? Zerner calls her hydration assessment WUT: Weight, Urine, Thirst.

Weight. Weigh yourself before and after a workout. For every pound lost, rehydrate with 16 to 24 ounces of fluid, she says. If you gained weight, “you probably overdid it in terms of fluids.”

Adds Lopez: If you lost more than 2 percent of your body weight, you didn’t drink enough.

Urine. “If it looks dark yellow, like apple juice, you’re probably dehydrated,” Zerner says. “If it’s the color of lemonade, you’re good to go.”

Thirst. Zerner says she likes the idea of focusing on drinking when you’re thirsty, but we’re not always “mindful and paying attention,” she says.

One problem with focusing on drinking only when you’re thirsty, Lopez says, is that some people “feel a thirst sensation that’s not always accurate.” They might be running a race and feel the need to stop at every water station, rather than some who miss them and might need water.

“They might not be able to ask themselves, ‘Am I thirsty right now?’ It’s a good indication for certain people, but not in all circumstances.”

Carey thought he’d been drinking plenty of water when he crossed the starting line of the Tour des Fleurs race in September 2013. He’d been training for the Dallas Marathon, so the 20K distance was nothing new. So he was surprised, as he says, 10 miles in when “things were a little swimmy and my vision was a little crossed.” He collapsed on the route.

“My arms were shaking. My legs were shaking. I was terrified,” Carey says. “The last thing I thought was dehydration. I was working with a trainer and he had me drinking two gallons a day. It turned out to be an electrolyte imbalance. They gave me four liters of fluid and I was back on my feet in 30 minutes.”

He says he was almost in renal failure. Turns out his problem was caused by consuming energy drinks with extra caffeine, which, he says, “naturally dehydrated me.”

Fast-forward to earlier this year, when he was running a marathon in China.

“The water is a huge concern over there,” says Carey, who has set a goal of running a marathon on every continent. “You don’t brush your teeth with sink water; you don’t do anything. What they had for the electrolyte drink was mixed in a big 10-gallon tub. No way was anyone going to try it. I muscled through; I doubled up on [bottled] water, which I shouldn’t have done.

“I started getting the shakes. I didn’t feel good. I had the same initial symptoms as dehydration. I kept piling water on water till it was stuck to my gills. My body said, ‘You know what would feel good right now?’ And I threw up.”

Twice. He felt better, and better still after asking a fellow runner who was taking a break for part of her “big sourdough pretzel with big rock salt. I just sucked off the salt. Within minutes, I felt fantastic.”

Since then, he “played around till I found what works for me,” he says.

What he calls his “Goldilocks number, my Sleep Comfort number” varies, he says. Which, Zerner adds, is true of everyone.

“I don’t think people need to worry so much about the precision throwing down two liters or three liters,” she says. “There will be days when we need more and days when we need less.”

Thirsty for details?

Water is best. Diet sodas and iced tea are diuretics. And who wants to be making more bathroom stops on a run?

Electrolyte drinks are (sometimes) OK. In moderation. If you’re working out strenuously for an hour or more. “We absolutely overdo the sports drinks,” says Meridan Zerner, registered dietitian at Cooper Clinic.

Don’t overguzzle. As a general rule, Luke’s Locker recommends its runners drink two or three cups of water two hours before workouts, another cup 10 to 15 minutes before and a few ounces every 20 minutes or so while working out.

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