5 Tips for Staying Hydrated in the Heat

You’re in the middle of a long run or ride. The sun is beating down on you and the humidity makes every breath feel like it’s being taken underwater. All of a sudden your legs turn to Jello, your head starts pounding, and you start to feel like you can’t take another step. You can tell immediately: you’re dehydrated. You reach for your bottle and try to push fluid and electrolytes, but, unfortunately, it’s likely too late to save your workout.

We’ve all been there. But can you avoid it? Absolutely!

While hydration is incredibly important any time you exercise outside, it’s even more so when you are working out in the heat. The hotter it is, the more you will sweat and the more fluid and electrolytes you will lose. Therefore, you have to pay extra close attention to your hydration needs when the mercury rises to ensure you do not lose performance to dehydration.

To that end, we’ve compiled a list of five tips you can use to make sure you stay hydrated, healthy, and firing on all cylinders while taking advantage of those long summer days.

Replace What You Lose

The key to staying hydrated during exercise in any weather is to consistently replace the fluid and electrolytes that are lost through sweat. The amount of fluid and electrolytes required to stay hydrated will vary widely from person to person, workout to workout, and season to season. Therefore, the most important thing you can do is experiment with different fluid and electrolyte combinations to see what works best for you in any given situation.

One of the best ways to nail down how much fluid your body requires during exercise is to periodically weigh yourself before and after your workout. If you are hydrating adequately, you should not lose more than a pound or two (2-5 lb if you weigh over 200 lb); if you’re losing more, that’s a clear indication that you need to drink more. By tying the quantity of fluid you consume to your weight change during exercise, you can dial in exactly how much you should be drinking to keep weight loss--and dehydration--to a minimum. In turn, this will help ensure you are replacing enough of what you lose during exercise so as to not jeopardize your health and overall performance.

In terms of electrolytes, it is best to start with the well-established minimum of 400mg of sodium per hour of exercise and build from there. For Stage, this is somewhere between Level 7 and Level 8 on the dial, but you can take it all the way up or all the way down to hone in on exactly the electrolyte payload that works best for you. If you’re a salty sweater, it’s a safe bet you will find your sweet spot is well-above 400mg, while your running mate’s hydration might be well-maintained with nothing more. One note: the risks of consuming too many electrolytes--namely, gastrointestinal distress--are far outweighed by the risks of dehydration, so if you’re going to miss during this period of trial and error, miss high.

Water Alone Isn’t Enough!

When the body becomes dehydrated, it triggers the thirst reflex. You know the feeling--parched throat, dry lips, feeling like you need to swallow but can’t. Paradoxically, if you respond to this sensation by reaching for plain old water during sweaty exercise, as many are wont to do, you are actually doing yourself a disservice. Drinking water will quickly turn off your thirst mechanism while triggering your kidneys to produce urine. The result is that you will drink less and lose more, just the opposite of what should happen when you are working up a sweat. Keep in mind that the two major avenues of electrolyte (mineral) loss are through sweat and urine. Consuming only water during exercise dilutes the body’s electrolyte content, turns off thirst prematurely, and increases the risk of performance-sapping dehydration. Of course, when plain water is the only option you have, then drink up, but remember water’s limitations in maintaining hydration and electrolyte balance.

Fortunately, it’s pretty simple to avoid this Catch-22. If you add the appropriate amount and mixture of electrolytes to the fluids you consume during exercise, you can sustain your thirst response and reduce urine production in the kidneys. In short, you will naturally drink more, lose less, and stay better hydrated! It’s important to remember here too that variety is key, especially on longer rides and runs. You can still consume straight water occasionally, just make sure you are also consuming enough electrolytes to help replace some of what is being lost in sweat and urine. And to echo our earlier point, everyone--and this holds especially true for higher-level athletes--has their own unique hydration needs. Sweating rates and electrolyte content vary widely from person to person, as some athletes lose enormous volumes of sweat and the electrolytes that go along with it while others may lose only a fraction of that amount. Therefore, it’s important for you to know how much fluid and electrolytes you should consume during a hot workout to make sure you meet your individual needs.

Account for Alcohol and Caffeine Intake

When you know you’ll be working out in the heat, it’s best to avoid morning lattes and martini lunches. Alcohol and coffee are both diuretics, meaning their consumption triggers the kidneys to produce urine, potentially draining your body of vital fluids and electrolytes. If left unchecked, this uptick in urine production can have a dehydrating effect, especially if you are engaged in vigorous exercise later in the day. However, you don’t have to go completely cold turkey--if you are really craving a morning cup of joe or a nightcap, just make sure you factor that caffeine or alcohol intake into your hydration protocols during exercise. For most people, caffeine is a very mild diuretic and not a major challenge to hydration. The important thing to remember is that when you’re anticipating a very sweaty workout or competition, it’s always best to be well hydrated, so limit caffeine intake and avoid alcohol.

Workout in the Morning or Evening--and With the Right Gear

Generally speaking, the more you can avoid working out in the heat of the day, the better hydrated you will be. This means working out in the early morning or evening, sticking to shadier streets and trails, and avoiding the temptation to sneak in a run at lunch when the sun is high in the sky. If midday is your only option, you can consider working out indoors on a treadmill or stationary bike to avoid the high noon heat. Working out in the heat is critical to becoming heat acclimated, an important response that protects health and improves performance, but you don’t have to choose the hottest conditions to reap those benefits.

Regardless of when you work out, it’s also important to make sure you are wearing lightweight, sweat-wicking clothing that facilitates evaporative cooling. Hats, sunglasses, and neck gaiters can also be used to keep direct sunlight off your skin.

Hydrate Before, During, and After

One of the keys to staying hydrated during the summer months is to consume a variety of fluids throughout each day, not just during exercise. If you consume fluid and electrolytes consistently throughout the day, you’ll have a solid “base” of hydration to build off of during your workout. Conversely, if you only start drinking water after you’re already a few miles into your run, it’s going to be next to impossible to avoid progressive dehydration. Paying attention to hydration outside of the hour or two that your body is in motion will go a long way towards allowing you to perform--and recover--at your best.