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Summer Hydration and Sodium


Dr. Andrew Porter likes being in marathons and triathlons — and he says this heat doesn’t bother him.

“I like the heat!” said Porter, associate director of Via Christi Family Medicine and assistant director of the Via Christi Sports Medicine Fellowship. “My wife thinks I’m nuts.”

His wife, Mandy, also is a runner and they have five active youngsters. Porter said his lifelong interest in sports helped lead him to Sports Medicine. His experience in long endurance events has given him a lot of practical knowledge for staying in the game, especially in hot weather.

For adequate hydration, an athlete needs:

  • 16 oz. of fluids two hours before practice or a game,
  • 16 oz. of fluids 20 minutes before practice or a game, and
  • 4 to 8 oz. of fluids every 20 minutes during practice or a game.

“I tell anybody exercising in the heat, ‘Weigh yourself before a game or a long run, and weigh yourself afterward, then replace every pound lost with 16 oz. of fluid over the next 24 hours.’ ” Porter tells his patients and the athletes he works with that the well-hydrated person’s urine is very light yellow to clear in color. “That’s one way to remember to drink enough fluids,” he says, and an immediate way to recognize a problem. But hydration is only one part of the equation. “We’ve gotten better at having people drink water, but a lot of people ignore replacing sodium. It’s equally important to make sure your electrolytes are in balance.”

  • If you’re going to exercise more than one hour, first drink 12 oz. of a drink like Gatorade or Powerade, specifically to get ½-1 gram of sodium per liter of fluid.

Ironman and other triathlons are sometimes about eight hours for the professionals and can be as long as 17 hours for a regular person, Porter said. In such long races, runners consume lots of water and can lose a lot of sodium. He has another easy solution:

  • If you start to cramp, take a salt tablet until you stop cramping.
  • If you stop cramping halfway through the tablet, spit the rest out.

Salt tablets are available over the counter at a pharmacy.

Prevention, prevention, prevention

Porter stresses prevention because if you develop heat stroke, heat exhaustion or other heat-related illness you are more susceptible to another heat-related illness. But that’s not the only risk.

“When you aren’t hydrated, or your electrolytes are off balance, there is a tendency to develop another type of injury like an ankle sprain, because your body just isn’t performing as it should.”

What about the kids?

Youngsters should get fluids when they’re playing outside, about 4-6 oz. every hour. An easy way to figure it is to just cut quantities recommended for adults in half.

“Even in the pool, where they won’t perspire as much or have as big a temperature change, they still need to hydrate,” Porter said.

And the rest of us?

Porter said, “Whatever is a big event for you, like mowing in 100 degrees, make sure to hydrate both before and during that activity.”