Runners sweat a lot, and of course need to replace their sweat with fluid to stay in hydration balance. You were probably still in grade school when you first learned that humans can live far longer without food than without water. The lesson made a strong impression, so it’s no wonder that you listen carefully to messages about runners and their special hydration needs. It all sounds so logical.
We live in a culture that’s obsessed by fluid consumption, which is heavily promoted by commercial drink producers. We’re almost as obsessed by fluids as we are by processed foods, also highly advertised. The difference is that we consume lots of water, an actually healthy and natural fluid. You can’t say the same about processed foods. Which of them are healthy and natural?
Of course, there’s a simple explanation for this difference. Coke, Pepsi, and other global corporations own a number of popular water brands. The companies are happy to market and sell bottles full of water that otherwise flows freely from our household faucets. Not to mention the carbonated sugar waters, sugar juices, whole juices (containing heavy doses of sugar), sports drinks, and energy drinks they also sell.
Right behind them, the coffee, tea, and beer companies are just as eager to have us consume their beverages. No wonder all the people you know seem to be sipping one fluid or another all day long. And constantly telling each other to beware the hazards of dehydration, which supposedly include headaches, fatigue, dry skin, obesity, and a nearly infinite list of imagined conditions.
Pity our poor Paleo ancestors. How did they ever survive through long days of food-gathering under a hot African sun without a liter bottle of fluid in each hand? Oh, here’s a thought. Maybe humans are well adapted for regular short periods of dehydration. Maybe Paleo people drank from a stream in the morning, walked and grew dehydrated during the day, and returned to the stream at night. For about two million years before someone invented the household water faucet.
I grow too facetious. Here’s the point. Few of us are seriously dehydrated. If we were, we’d weigh a half pound less every morning, and that’s not happening. Good hydration is absolutely essential to good running, and also ridiculously easy.
Drink water (mostly) when you are thirsty or notice your pee is yellow (rather than clear or straw-colored). As much as possible, avoid drinks with extra sugar or fat calories. Drink alcohol only with friends, and in moderation.
Don’t overhydrate in races: Runners once believed they should drink as much as possible in races to maximize their performance. Then, in the early 1990s, we learned that it is possible (and dangerous) to overdrink. This causes a condition called hyponatremia, also known as “water intoxication,” which can produce a dangerously low blood sodium. This, in turn, can lead to brain swelling and even death.
Severe hyponatremia is rare, but occurs most often during marathons and ultramarathons and among runners of small size (more women than men). If your stomach is sloshing or a ring is feeling unusually tight on a finger, consider it a warning sign.
Don’t drink as much as you can. Don’t drink at every water stop just because you can. And don’t expect water to perform miracles like relieving muscle fatigue. It can’t do that. The best guideline: “Drink when you are thirsty.”
Follow the 2 percent rule: Recent research has shown that runners can perform their best and maintain full health up to the point of 2 percent dehydration. That’s quite a bit of fluid you don’t have to drink while you’re running. For example, a 150-pound runner can lose 3 pounds of water, 48 ounces, without worry. You’ll run faster because you won’t have to slow and walk at the water stops. You’ll probably feel better as well, and suffer from fewer episodes of race nausea.
Use tried-and-true sports drinks during races: In races lasting longer than an hour, consume a sports drink for its sugars and electrolytes. You don’t need sports drinks in shorter races.
In half marathons, marathons, and other long events, grab a sports drink when you are thirsty, or on a reasonable schedule, say every 20 minutes. (More often in hot weather.) Smart, forward-thinking marathoners search out the drink that will be available at their upcoming race, and then practice with it on training runs.