How, when, and what you drink might be dehydrating you. – By Molly Hurford
As late-summer temperatures soar, you might be tempted to add an extra water bottle to your ride to stay better hydrated. But before you do, you should know a few things about how your body actually absorbs fluid.
Hydration and fluid absorption are not the same
Just drinking a ton of water doesn’t mean that you’re necessarily able to use all of it, explains Stacy Sims, PhD, founder of Osmo Nutrition. Yes, you want to drink enough, but to achieve a well-hydrated state, you actually need to absorb the fluids you’re consuming.
“Being hydrated means that you have all of your total body water compartments at a relatively even balance,” she says. “Fluid absorption is drinking something and pulling that fluid into different compartments.” Otherwise, you’re just giving yourself more reasons to pee.
You need more than just water
When considering the water in your body, think about this: While it’s true that we are primarily made up of water, none of it is plain H2O. So for your drink to be easily absorbed within the gut and to spread into the cells that need it most, it needs to have the right mix of water and electrolytes.
“You primarily need some sodium and a bit of glucose in a drink,” Sims says. “A bit of sugar in with the electrolytes gives the best absorption so that you’re able to pull that fluid across and mitigate dehydration issues.”
Drinking your kilojoules may be hurting your ride and your gut
Just because you shouldn’t only drink plain water doesn’t mean that you should opt for calorie-laden sports drinks. These sugary beverages sit in your stomach and draw water from other spaces in the body – essentially dehydrating you in the process.
“You should never be looking at your drink as a calorie source because then it’s not going to hydrate you. You’ll end up pulling water from other places to dilute it,” Sims says.
Women may need a different drink mix than men
Sims is well known for saying, “Women are not small men.” She’s based much of her research and product development on the concept, specifically when it comes to women’s needs for sports drinks.
“Women can’t absorb as much fructose as men, so sports drinks containing fructose tend to contribute to GI distress and dehydration in women. It’s like dumping a bunch of carbohydrates into your body,” she says. The fructose hangs out in the intestines until you can activate it.
If you’re a female cyclist shopping for a sports drink, steer clear of those that are high in fructose.
Pregame for your ride with a pinch of salt
If you love salty food, you’ll love Sims’ next piece of advice: Drink water with a pinch of sea salt throughout the day, especially before a ride, to prep for maximum fluid absorption during your ride.
During exercise, your body is busy sending blood flowing to muscles, instead of expending energy moving fluid across the intestines. However, during rest, that blood flow diversion doesn’t happen quite the same way. So there’s adequate glucose in the stomach and intestines to help transport water, as long as there is also enough sodium present.
“If you drink water with a little bit of salt while not exercising, it actually facilitates the fluid being absorbed,” Sims says, “because you don’t have to pull sodium from other places into the intestines for absorption. It’s already right there.”
Over-drinking can be as bad as under-drinking
Over-drinking is a problem for riders, both in terms of hydration status and, if you’re using a sugary drink, weight gain.
“New athletes who have gone through programs like Team in Training often over-drink as they try to improve performance,” Sims says. “This is because it’s been instilled in them to drink 250ml every 15 minutes, regardless of what they’re doing and who they are.”
The idea that athletes should drink X amount of fluid per hour is a mistake, but unfortunately….
… There’s no perfect formula for how much to drink
There is no simple calculation to determine exactly how much you need to drink on a ride. Your gender, weight, sweat rate, and fitness level are all factors, as are the conditions you’re riding in (hot, cold, wet, or dry) and the type of ride you’re doing.
Drinking just the right amount is a game of trial and error, but consulting an expert, like a sports nutritionist or even your coach, may help get you closer to perfect hydration status.