What is the best way to stay hydrated? We asked an expert
NORTH TEXAS (CBSNewsTexas.com) - A nice, cold glass of water can certainly help you beat the summer heat and Dr. Craig Crandall says it's as simple as that.
"What's best is water," he said. "For most individuals, water is more than adequate to keep individuals hydrated. Now, of course, there is liquid in our foods but you'd have to eat a lot of celery to match what you might drink in a cup of water."
He says the exception would be those who are staying outside for a long time and are sweating a lot, for example athletes. In that case, he recommends maintaining a healthy level of electrolytes, with drinks such as Gatorade or Powerade.
"When we sweat, our body releases not just water, but also primarily our sodium and chloride ions—what we normally think of as salt. Those are really important for our nerves to function properly. And so, if we're sweating out sodium and chloride and we're not putting them back into our bodies, then, at some point, we can actually reduce those levels to the point at which it's detrimental to us," he said.
Crandall, who is a cardiologist and professor at UT Southwestern Medical Center, conducts research at the Institute for Exercise and Environmental Medicine at Texas Health Presbyterian. He does research, which is funded by National Institutes of Health, on temperature regulation and why older individuals are at at the greatest risk for heat-related injuries and death during heat waves, like we're experiencing now.
He says the elderly population—ages 65-70—account for 70% to 80% of heat injuries. Crandall has found that's because elderly folks may not recognize they are dehydrated and are less likely to drink enough water, not to mention slow skin blood flow responses.
"By and large, it's our oldest population that's at greatest risk, and that's almost entirely because they don't sweat as well, and they may be less likely to drink," Crandall says. "Older individuals' perception of thirst is reduced and so they're less likely to adequately hydrate because they don't perceive that they are dehydrated. Also, if our older population have urinary incontinence, they're going to reduce their water intake because they don't want to have to go to the bathroom or have accidents as much, and so they voluntarily reduce that content."
How hydrated are you?
Outside of older individuals, Crandall says good markers of how hydrated, or dehydrated, you are starts with how thirsty you are. Beyond that, the color of your urine will tell you your level of hydration.
"Your urine should be a light, straw color. Not a dark, deep color," he explained. "It should be light and it should not be dark. If it's dark, that tells us that you are dehydrated and you should drink more [water]."
The biggest myth about staying hydrated is that sweating is bad, according to Crandall.
"Our main mechanism for regulating temperature is sweating and if we are not hydrated appropriately, we don't sweat very well," he says. "Sweat is what we use to keep ourselves cool."
So you may be wondering just how much water you need to drink in order to stay adequately hydrated. The CDC says the amount of water you need varies depending on a variety of factors: age, weight, physical activity, even what you eat in a day.
While Harvard Medical School, the Mayo Clinic and the Institute of Medicine have all recommended women intake about 11.5 cups (2.7 liters) of water a day from all foods and liquids and men intake about 15.5 cups (3.7 liters) a day, Crandall says 8-10 glasses of water a day should suffice for the everyday, typical person.
Only 22% of adults reported drinking 8+ cups of water a day in a 2007 CDC survey, and some 35% said they drink 4 to 7 cups of water a day. Meanwhile, 36% said they only drink 1 to 3 cups of water a day and 7% of adults reported having no daily consumption of drinking water.
Our bodies are made mostly of water. It helps maintain the functioning of your organs, regulates your body temperature, lubricates your joints and helps your body rid itself of waste, among other things. If you're not consuming enough water and you start to feel thirsty, the CDC says at that point, you're already behind in fluid replacement.
Avoiding heat exhaustion and heat stroke
Typically, the biggest and earliest sign of not being hydrated enough is a headache, according to Crandall. He also says confusion is a big sign of heat exhaustion or a heat stroke coming on.
"Heat stroke is a real severe medical condition where individuals typically have some cognitive dysfunction. They could be unconscious, they could be mentally incapable of making decisions," Crandall explained. "Heat exhaustion is more of fatigue. You're still able to, in most senses, make good decisions on your own; you're feeling lethargic; you're feeling tired; you've got headaches. But heat stroke is a severe condition where there is neurological deficits and so, that's the threshold that I typically use."
He says the best way to avoid these heat injuries is to get out of the heat.
"Get out of the heat. That's the most important thing. That's No. 1," Crandall says. "You can drink water all you want. If you're still in the heat, water's gonna be helpful, but it's not going to be anywhere near as helpful as you getting out of the heat."
Crandall suggests individuals identify a place where you can keep cool with air conditioning such as the cooling centers, the movies, the mall, or where you can find water sources, like splash pads.
