Why is hot weather running so stinking hard and what can you do to make it easier for yourself? Today I want to talk about hot weather running or hot weather exercise in general – why it’s hard, what’s happening physiologically, and what you can do to work with it (not against it) during this time of year.
Hot weather is around the corner if you’re in the Northern Hemisphere, or you might be right in the middle of it, sitting in heat and/or humidity, feeling like your running or cardio or training goals have gone right down the drain with this heat.
Let’s talk about heat and humidity and understand what’s going on in your body so you can train smarter, not harder.
When you are exercising in heat and/or humidity, your body has to work overtime in several ways:
Your body has to work against its internal core temperature, bringing heat that you’re producing in your muscle tissues from your core outward to your extremities and releasing that heat into your environment.
When you have a hotter environment, it’s going to be harder because your personal temperature is elevated from the heat of your environment.
This is even more challenging if you’re training in heat AND humidity. When that heat is trying to dissipate into your environment, the humidity and moisture in the air, combined with the moisture on your skin, makes it hard to release that heat. You’re almost holding it in your body and system.
This is why East Coast or more humid climates have such a harder time with heat and humidity – the combination together increases the difficulty of your body’s ability to cool itself.
When you start sweating, you start losing blood plasma – the watery component of the blood in your body. Your blood is responsible for delivering the oxygen you’re breathing through your bloodstream into your muscles so you can produce energy to keep moving forward.
When plasma volume decreases:
Not only are you having a hard time cooling yourself, but your body is also increasing its heart rate because it’s losing that watery component of your blood and starting to have to work harder to produce the same amount of oxygen and energy supply that your body was delivering in a cooler or less humid environment.
The result: You have a higher exercising heart rate, experience cardiac drift, or have to slow down because your body cannot keep up with what it needs to cool itself or produce the energy needed to sustain your activity.
This can seem really frustrating – and it IS really frustrating. Trust me, I trained for races for years in Georgia, which is known for being very hot and humid. I get it. It is really hard, and it does suck.
Heat and humidity mask fitness. Do not judge your paces, your efforts, or your fitness on these hot and humid days. Recognize that heat is masking fitness, and that’s being compounded by the fatigue of your training.
You need to trust that it’s not a bad thing to slow down or go easier because of this.
A lot of people will use arm sleeves and different types of materials that are more moisture-wicking to keep themselves cool. Sometimes it seems counterintuitive to wear more layers, but people who live in desert conditions often use clothing that reflects the sun and covers their body, especially because of heat and sun exposure.
In many cooling systems, you can:
One of my personal favorites is always running with a bandana. I do this in general because it helps with sweat and keeps hair from running down my shirt, but in the summer, I sometimes wrap ice in those bandanas.
They also sell ice bandanas or cooling bandanas that you can freeze and put around your neck. Having some sort of cool water or ice on your arms or neck can make a significant difference.
I will frequently:
Personal example: During my 50-mile race when it was extremely hot, you can see in the video that I dunked myself in every stream or creek I came across during the middle part of the day (between miles 20-30). I would continuously cool myself to keep that core temperature down and use the water to help release heat into the air.
I know you guys aren’t going to like this, but the solution is slowing down and using heart rate as a gauge. You might need to slow down to where your heart rate is lower and easier.
Important: Running in the heat is more stressful on your body. You shouldn’t just say, “Oh well, it’s hot so my heart rate’s higher and I’m working harder, so I should just ignore it and keep going.”
Use a combination of:
If your heart rate is drastically increasing or drastically elevated all the time, you might need to slow down to adjust for that.
It’s not uncommon to have to run slower in the summer. Between the dew point, heat, and humidity, your paces during the summer can slow down by upwards of a minute slower than your normal zone 2 or easy pace.
That pace you might already be running and feeling frustrated with because it feels too easy or too hard to maintain? It’s not uncommon to have to slow that down even further in the summer.
Something I do a lot is take more walk breaks in the summer. If I’m starting to feel overheated or beat down from the heat, humidity, and sun, I’ll just take a 20-second walk break in the middle of my run and then keep going.
Sometimes you just need to do that, and there’s nothing wrong with it. You’re not losing fitness or “not a real runner” because you have to take a walk break.
If you are seeing a lot of cardiac drift or your heart rate is spiking all the time, especially if you’re a heavy sweater or heavy salt loser, you might want to start bringing water on more of your runs, including your short runs.
Remember, that blood plasma is a water component of your blood. You might be losing a lot more sweat, and that heart rate might be increasing due to dehydration.
Bring water even on runs less than 60 minutes. Sometimes we don’t typically bring water unless it’s an hour or more, but if you’re running in heat and humidity, it’s not a bad thing to bring water for 30, 45, or 60-minute runs.
Consider electrolytes for runs an hour or more, especially if you are someone who loses a lot of salt in their sweat.
I personally need more salt during running, especially in heat and humidity, than I realized in the past. It’s not uncommon for me to:
Be prepared to fill your water more frequently, drink more frequently, and keep that hydration up. You can use your heart rate as a sign that hydration is starting to drift.
Morning running: Cooler temperatures but potentially more humid
Afternoon/evening running: Less humid if you live in a humid place, but also hotter
You’ll need to gamble and figure out what works better for your specific climate and personal preferences.
It takes about two weeks to adapt to heat and humidity. I would highly recommend:
Personal example: Last year when I moved from Colorado back to the East Coast, I had been training in heat in Colorado, but it’s very different from heat and humidity. I remember taking that first week or two really easy and recognizing that I felt completely terrible on every run as my body adapted.
If you are training for a race or event that is going to take place during a hot climate environment, I really encourage you to train and adapt to that to some degree.
Don’t just avoid the heat if you’re training to race in it. That doesn’t mean go into it unsafely – being overheated or heat stroke is very real, and dehydration is very real.
Be smart about:
Give your body grace, hydrate it, cool it, understand physiologically why this is so hard on you, and make sure you adjust your pace and intensity and training in a way that accounts for this shift in climate that comes every single year.
Recognize that the fitness you’re developing and gaining – even when it’s hot and you feel like you’re not gaining fitness and it feels really terrible – once fall comes around, we call it “fast fall” for a reason. Suddenly you can run so much faster, and all of that fitness was completely worth it throughout the whole summer.
Slow is relative. Easy is relative. There’s nothing wrong with running your runs “too slow” or having to take walk breaks or having to adjust to account for the heat and humidity.
You’re not a bad person or a bad runner. Everyone has to do this. If anything, it will give your body some grace and space to adapt and handle the environment and climate it’s trying to train and perform in.
I keep reiterating this because I know so many of you do exactly this: “Oh my gosh, I’m terrible, I’m horrible, what happened to me, I’m losing fitness.”
As someone who’s trained for races throughout the summer more times than I think I should have (especially living in the southeastern US): It sucks, but you actually do adapt to it, you do get better, and you do show up in fall with so much fitness if you just stick with it.
It’s also okay if you hate summer running and prefer to run in the winter. Summer can be your off or down season.
I know a lot of people who flip their years, especially in places like Florida, Arizona, or Texas. They run a lot more in the winter because they have milder winters versus brutal summers.
You can segment your years and choose:
That’s also perfectly okay to do.
Immediate strategies:
Long-term adaptations:
You can’t change the heat and humidity, and what it’s doing to your physiology is just going to happen. Don’t beat yourself up for having to go slow or easy.
Heat and humidity mask fitness. The fitness you’re building during these challenging conditions will absolutely show up in the fall, and it will always be worth it.
Don’t avoid heat training if you’re planning to race in it, but take care of your body, be smart, hydrate, and recognize that working with your environment (not against it) is the key to successful summer training.
Ready to nail your summer training with a plan that accounts for heat, humidity, and real-world conditions? Check out The Lyss Method for programs designed to help you train smart in any weather.
Keywords: hot weather running, summer running tips, running in heat and humidity, cardiac drift running, heat adaptation training, summer training strategies, running hydration tips
I’m Exercise Physiologist, sports nutritionist, weight lifter, and ultra runner. I am here to bring science to your training in a no-nonsense way. I have helped thousands of women crush big lifting goals, cross race finish lines, and even do both. I’m here to help you do the same!
Get the free macro calculator
