Stay Safe During Hot Weather Workouts with Proper Hydration

How to Stay Safe During Workouts with Proper Hydration 

When you exercise in the heat, don’t skip drinking water. It seems obvious, but the research on hydration and hot weather show a few mixed messages. In this article, we cover the latest research surrounding hot weather workouts and hydration, plus how to stay hydrated.   

Essential Takeaways

• Springtime is knocking on our front door! Now’s the time to start thinking about how we’ll (safely) sculpt those beach bods.
• Sure, hot weather is nice, but it can be dangerous without proper hydration. Strap your learning cap on and keep reading to learn more about our easy-squeezy secret weapon to safe hot-weather workouts!

Even in cool weather, mild dehydration can decrease sports performance and extend recovery times (1). If you want to stay safe for your next outdoor workout, then this article is for you. Here’s how to beat the heat with proper hydration:

• What Happens to Your Body In Heat and Humidity?
• How Much Water Should You Drink?
• Is It Possible to Over-hydrate?
• What Is Heat Acclimation?
• Does Under-hydrating Actually Help You Acclimate Faster?
• The Truth About Hydration and Hot Weather Workouts
• 5 Daily Hydration Tips
• Hydrating Before Hot Weather Workouts
• Hydrating During Hot Weather Workouts
• Hydrating After Hot Weather Workouts
• Signs and Symptoms of Dehydration
• Signs and Symptoms of Heatstroke

What Happens to Your Body In Heat and Humidity?

Anyone who’s ever exercised outside in mid-July knows that heat and humidity make it tougher. Each step feels heavier as you struggle to stay cool. To maintain a safe body temperature, you have to get rid of the excess heat ASAP. The heart pumps blood to the skin’s surface, you sweat like a banshee, and as the sweat evaporates you start to cool down.

Viola! Instant A/C!

But humidity makes it more challenging… When the air is too moist, your sweat struggles to evaporate and cool you down. This makes drinking fluids even more important in humid weather.

How Much Water Should You Drink?

In hot, humid weather, you can lose buckets of sweat---over a quart an hour to exact. This means you should drink roughly three cups of electrolyte-enhanced water each hour during moderate to intense exercise.

With that said, there really aren't any golden rules for how much water to drink. The best protocol is to listen to your body and take little sips of water throughout the day. When you exercise, drink a little more.

The trick is to stay ahead of the game and avoid guzzling too ungodly amounts. After all, there is such a thing as overhydrating…

Is It Possible to Over-hydrate?

Yes! If you experience nausea, vomiting, bloating, or weight gain, you could be on your way to overhydration and other life-threatening complications.

Hydration science has come a long way over the decades. Shockingly, back in the 1970s athletes were advised to avoid drinking water before and during exercise. Where’s a face-palm emoji when you need one!?

Fast forward to a few decades later and the pendulum has swung in the opposite direction. Athletes started to overcompensate and drink way too much water, leading to water intoxication and hyponatremia (low blood sodium levels). This dangerous combination of too much water and too little sodium can wreak havoc on your health.

In 2002, a female runner died in the Boston Marathon due to water intoxication (2). Water intoxication can happen when you drink 3+ quarts of water or more during a 4-hour race. That’s enough to gain weight...and it’s way, way, wayyyyy too much!

What Is Heat Acclimation?

Heat acclimation is the body’s natural process of coping with hot temperatures over time. Total acclimation to hot climates can take several weeks. Over time, you shouldn’t have to sweat as much in order to stay cool.

Does Under-hydrating Actually Help You Acclimate Faster?

It’s time to address another common myth: that drinking less water during hot-weather training accelerates heat acclimation. Believe it or not, some athletes used to swear by it.

In their defense, there is at least one study that found positive results about under-hydration and heat acclimation (3). But the majority of research tells a much different story about hydration and hot weather...

The Truth About Hydration and Hot Weather Workouts

A 2018 study found that under-hydration didn’t help at all with heat acclimation (4). The team predicted that under-hydrating would cause more stress on the athletes’ bodies. They were right.

Athletes who drank less water had higher levels of inflammation, cortisol, and other markers of stress---not to mention feeling quite thirsty. According to the study’s authors, “Not drinking during hot workouts caused more physical stress but no particular physical benefit.” Extra stress can also increase the risk of respiratory infections and general fatigue, and neither of these is good for training.

The bottom line is, drinking less water won’t help you perform better in the heat...period.

5 Daily Hydration Tips

Do you struggle to drink enough water throughout the day? Regardless if it’s hot as hell or cool as a cucumber, your body needs a steady drip of fluids.

Stay hydrated with these daily hydration tips:

Make Water Convenient

With ice, no ice, a straw, glass bottle, copper bottle, customized bottle---whatever floats your boat. A lot of the time people don’t hydrate because they don’t want to take the time to walk to the kitchen, grab a glass and fill ‘er up. Having a handy water bottle helps.

Invest in a Filter

Filters make your water cleaner and tastier, which brings us to our next tip…

Naturally Flavor-ize Your Water

Lemon balances the body’s pH, plus it tastes delicious. If lemon isn’t your thing, try lime, berries, or mint.

Add Some Bubbly

Prefer carbonated water? Buy a soda stream and make your own seltzer water. They’re easy to use and more affordable than you think.

Squeeze in Some Electrolytes!

Find a flavorless electrolyte supplement and add it to the beverages you’re already drinking. The more you sweat, the more electrolytes you’ll need to drink.

Hydrating Before Hot Weather Workouts

If you go into your workout dehydrated, you’ll be playing catch-up the rest of the day. So make sure your body is fully loaded on fluids before you even break a sweat.

Drinking 16 oz glass two hours before your workout should do the trick. This gives your body plenty of time to flush out the extra fluids and avoid annoying bathroom breaks. Whatever you do, don’t wait until you’re thirsty to start drinking. You should be taking a piss every two to four hours throughout the day.

Hydrating During Hot Weather Workouts

You and your water bottle should be joined at the hip. Take little sips throughout your workout and don’t forget to add electrolytes.  

A good benchmark is to take a sip every 15 minutes. Your stomach can only process 5-7 fluid ounces every 15 minutes, so anything more than that just means more bathroom breaks.

The point is to stay ahead of the curve so that you never actually feel thirsty, without feeling like there’s a fishbowl in your belly. When you hit it just right, you’ll perform better, have more energy, and get fewer muscle cramps.

Hydrating After Hot Weather Workouts

Congrats! You finished your workout---now it’s time to recover. Electrolytes and hydration are essential to recovery. Dehydration, on the other hand, means more inflammation and more fatigue.

Did you know that on a hot day you can sweat 3-4 pints of fluid per hour? Hot diggity!

Your goal should be to drink at least half of that during your workout and replace the rest afterwards.

Pro tip: make yourself a protein shake with flavorless electrolytes---this will give your cells the amino acids and minerals they need to repair tissues and remove waste products.

Signs and Symptoms of Dehydration

Symptoms like headaches, drowsiness, and muscle weakness can start at just 2 percent fluid loss, and it only gets worse from there (5).

Common Symptoms of Mild Dehydration 

• Thirst
• Dry mouth
• Fatigue
• Poor cognitive performance
• Muscle weakness
• Decreased urination
• Dizziness
• Headache
• Digestive issues

The good news is that you can usually treat mild dehydration on your own by drinking electrolyte-enhanced water. But what happens when dehydration gets worse? Severe dehydration occurs at 10+ percent fluid loss, and it can come out of nowhere on a hot day.   

Common Symptoms of Severe Dehydration

• Extreme thirst
• Rapid heart rate
• Low blood pressure
• Lack of sweat
• Dark urine
• Sunken eyes
• Irritability
• Confusion
• Delirium
• Lack of tear production
• Skin that’s shriveled and doesn’t “bounce back” after being pinched or stretched

Signs and Symptoms of Heatstroke

As you sweat to try and cool down, you dehydrate more quickly. Before long, you run out of fluids and electrolytes. Without the ability to sweat, it’s only a matter of time before heatstroke sets in.

As you sweat to try and cool down, you dehydrate more quickly. Before long, you run out of fluids and electrolytes. Without the ability to sweat, it’s only a matter of time before heatstroke sets in.

Common Symptoms of Heatstroke

• High body temperature
• Flushed skin
• Extreme thirst
• Inability to sweat
• Headache
• Dizziness
• Sluggishness
• Rapid heartbeat
• Disorientation
• Confusion
• Agitation
• Loss of consciousness
• Hallucinations      

Kids and older adults are the most at risk, but it can happen to anyone. To avoid heatstroke on hot days, drink plenty of electrolyte-enhanced water, stick to the shade and keep your workouts short (an hour or less). Happy sweating!