I don’t know what the weather is like where you all live, but here in Massachusetts the last few days have passed 90 degrees. Don’t get me wrong – I’ll take the heat over the massive snowstorms we had all last winter. But hot and humid weather can make it a bit tough to train outside. I’ve put together 4 top tips for running in the heat below. I know I get a bit sciencey at parts in this post, so forgive me if it sounds a tad impersonal – but I’m hoping this info is useful for you!
4 Tips for Running in the Heat
1. Hydrate properly
Drinking enough fluid is essential to staying healthy while exercising on warm days. If you’re working out for more than 60-75 minutes, it’s smart to take in fluid + electrolytes + carbohydrate. If you’re working out for less than 60 minutes, plain water is generally fine. If it’s a really warm day though and you’re out there less than 60 minutes, drinking an electrolyte beverage without carbs – like nuun tablets or something similar – might be helpful.
I’ve found some runners get nervous about drinking on runs, because many have seen media stories about overhydrating and getting sick from too much water intake (otherwise known as hyponatremia). That is a very real concern with serious consequences – however, dehydration is about six times more common in runners compared to hyponatremia.
The key is to drink enough to maintain the right balance; to prevent dehydration without risking hyponatremia. There’s no one guideline that fits all people for proper hydration. I can’t say drink x ounces per hour because we all sweat at different rates – person A may lose much more per hour than person B – so hydration recommendations really should be personalized.
My advice is to do a “sweat test” to see if you’re hydrating right on hot days – weigh yourself before and after a run in the heat. If you lost more than 2-3% of your body weight, you probably want to hydrate a bit more. If you stayed exactly the same or you gained weight, you should hydrate a bit less. If you lost about 1-2% of your body weight, you’re probably in the sweet spot of proper hydration.
Even with a sweat test, above all – pay attention to your body’s cues for thirst (dry mouth, craving water) and overdrinking (sloshing, nausea) – and be sure to honor those cues.
And of course, if you’re training and you start to experience any warning signs of heat related illness or hyponatremia, stop and get help. Heat exhaustion may present itself with lightheaded, dizziness, confusion, muscle cramps, nausea/vomiting. Hyponatremia often presents with similar symptoms, and can dangerously progress to issues like seizure or unconsciousness.
2. Acclimate for hot weather events
The first question I usually ask people when they’re planning to train throughout the summer for an event: Is your race going to likely be in warm weather too? If race day is almost always a cooler day, then there’s really no reason to subject yourself to training in hot weather. Do your training in the early morning or later in the evening when the temperature cools down.
If it is going to be warm on race day, though, it’s important to do some of your training in the heat so that your body can acclimate to the warm weather. It takes your body a bit of time to get used to running in the heat – about 2-4 weeks depending on your fitness level, training schedule, and the specific weather conditions. When you start exercising in the heat, start with a slower pace and reduced intensity at first. After a few weeks, your body increases plasma volume to help carry blood to the surface of your skin to dissipate heat, and you also become a more efficient sweater (starting to sweat earlier for cooling, and losing less sodium in that sweat).
All this being said, train smart even if your race will be in hot weather. If there is a major heat advisory out there, it’s not the time to try to prove your superhuman strengths with a mid-day long run.
3. Focus on sodium
Sodium is important for runs (or other exercise) lasting over an hour. In the heat, it becomes even more important since you’re sweating more frequently and losing electrolytes. Sodium recommendations are also hard to give as generalized advice, because the rate at which people sweat varies considerably, as does the concentration of sodium in a given amount of sweat. As a starting point, the ACSM recommends that you take in about 500 to 700 mg of sodium per liter of fluid you drink during exercise that lasts more than an hour. Most commercial sports drinks fall in this range.
If you’re a heavy salt sweater or you find yourself struggling in the heat, you may need a bit more. I generally recommend trying one of two options for this:
- Try a sports drink with a higher amount of sodium (for example Perform or Gatorade Endurance Formula)
- Add a pinch of salt (1/8 tsp) to your normal sports drink
You could also consider electrolyte tabs or capsules.
{Side note – I highly recommend sitting down with a sports dietitian (myself or others) who can help you figure out the right hydration, electrolytes, fuel etc for your particular body.}
4. Try a pre-exercise ice slurry
An ice slurry or slushy is basically just crushed or shaved ice mixed with water. Interestingly enough, this has been researched several times in sports nutrition journals. The findings are generally consistent that taking in an ice slurry before going out to exercise may keep your core body temperature cooler during your run. There’s less research on the role during a run, but on a really hot day I think (anecdotally) it could be worth a try if you’re running by your house multiple times (or the ice cream man swings by with some snow cones, haha).
Share with me: What are your tips for running in the heat? What tip above will you start to implement?
Chrissy Carroll
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The struggle is real when it comes to summer running! I have been working on trying to get some electrolytes in pre-run too when running in the evenings. Sometimes drinking water all day isn’t enough when it is so darn hot.
Thanks for the tips!
Great point. Paying attention to hydration and electrolytes throughout the day is a smart strategy so you start your workout in the best possible place!
awesome tips! I needed those for my run this morning. I agree that the heat can be tricky but I would gladly take it over the cold and snow any day. I need to look into more sodium prep for my workouts, I’ve been losing a lot of sweat the last few months and need to retain a little more during activity. There’s only so much water I can drink while teaching! Happy Tuesday, talk to you tonight!
Yes, the heat is a bit annoying but I definitely prefer it to icy snowy sidewalks and snow banks making it unsafe to run.
Great tips! I have been having a really hard time lately with the humidity… I’m going to try the Ice slushy 🙂
Go for it! Then come back and share how it worked for you. 🙂
I will definitely try that ice slurry! What a good idea. As someone who once got heat exhaustion from running in Tampa, these tips are SO valuable! Thanks for sharing!
Oh no, heat exhaustion is awful! Hope you recovered quickly.
Thanks for the great tips! The ice slurry idea is very interesting. I’d be curious how long it would help keep your core body temp lower.. like for a short 30 min run, or would it even help on a longer 60+ min run.
That’s a great question and I’m not 100% sure off the top of my head. In guessing it’d be beneficial regardless of length, because even for a really long run it’d still take a longer time for your body to get hot with the ice slurry compared to without it.
Great tips! My husband swears by salt pills. I like trying to extra-hydrate the day before a race and also during a race I drink an electrolyte drink called Fluid. It seems to keep me feeling less dehydrated.
Some people love the salt pills! (I’m partial to a higher sodium drink like perform.) I haven’t had a chance to check out Fluid but will have to give it a try.
so glad I stumbled upon your blog today! I’m about to go for a hot and sweaty run later and I am glad I found these tips.
So glad you found them helpful Dani! Hope you had a great run.
In Taiwan the heat was UNBEARABLE so yeah, I love my INDOOR – AC filled GYM! 😉
Haha yes, that’s the one tip I missed: find somewhere with AC!
All great reminders! I also recommend getting out as early in the morning as possible!
That’s very smart Michelle, mornings always feel way more comfortable.
I never heard of ice slurries! Sounds factual enough. You can also freeze a water bottle to bring on your run. You may need to wrap it in a paper towel or something at first, but eventually it will melt so you can have cold water to drink and something cold to hold/rub on the back of your neck if you get really hot.
Great tip Nicole!! Love that idea.
Really great tips, Chrissy! I totally agree about getting in salt and staying hydrated. I fade really quickly when I get dehydrated on summer runs. I feel terrible and just generally out of it when I get dehydrated. It’s amazing what drinking enough water can do to help keep you feeling good on your runs. Wonderful post with lots of great information!
Yes!! I know when I make a concerted effort to stay hydrated and use a higher sodium sports drink, I feel better in the heat.
Chrissy great tips. I really enjoyed this and learned some new verbage. Living in the Sonoma/Napa area it has been a pretty hot and dry summer. I have to run early in the a.m. the heat is just not my friend for running. Most races are here in the area and they start early, so my training time is pretty matched up with race time. I am still figuring out my electrolyte intake and what to use. Water and Nuun tablets are about it for now.
The Nuun tablets are pretty good for electrolytes! If I’m remembering correctly, I think one tablet has 360 mg of sodium.
Thanks for this. I must admit I am on the crappy side when it comes to running in the heat. It’s not that I cannot stand it, but I don’t enjoy it much. I usually wait until the sun gets weaker. Unfortunately here in Holland, since the days are very long in the summer (sunset at its peak is at 10:40pm), that means waiting for a little while:)
I’m definitely of the opinion that if you don’t enjoy it and if your races aren’t going to be in the heat – then definitely smart to train during cooler parts of the day and/or indoors. Whatever works best for you! Also, I don’t know how I’d handle a sunset at 10:40pm – I feel like my body would be so confused by it being light out that late, haha.