Living in Central FL, I am forced to take the good with the bad.
The good, of course, is running in the months of November, December, January, and February.
The bad, is running in the summer heat AKA the other 8 months of the year.
One thing I’ve noticed in the past few years, and something that I’ve been quick to point out to others that complain about running in the summer heat, is that I notice a big improvement each fall after sweating it out on my training runs in the summer.
And I’m not the only one that has seen the positive results.

Does Running in the Summer Heat Help or Hurt?
My Rationale for Running in the Summer Heat
When I first noticed this dramatic fall improvement in myself, I didn’t know what caused it.
Was it the cumulation of training finally paying off? Was it the cooler temps? Was it just a fluke?
But as I talked with fellow runners who saw similar spikes after several months of running in the summer heat, I started to think about what might be causing the improvement.
I chalked it up to the fact that when it’s hot, your body needs to cool itself by sending blood to the skin which results in perspiration. If more blood is being sent to the surface of your body, there is less blood going to the muscles which means they aren’t able to work as hard or as long.
Following this logic, as the weather cooled there isn’t a need to send as much blood to the skin for sweating so more blood was going to the muscles, and bingo-bango you’re able to run faster.
Turns out, there is a bit more of a physiological response that is responsible for you running faster after training in the summer heat.
The Doctor’s Take on Heat Training
Dr. William O. Roberts talks about your body’s response to running in the summer heat in Runner’s World recently:
Victor asks: I like to run at lunchtime during the summer. My friend told me that running in the heat increases your red blood cells, and that this is akin to blood doping, and as a result my PRs don’t count. I know he’s joking about doping, but wanted to know how running in the heat impacts blood cells.
Yes, your PRs do count. Heat acclimatization is quite different than blood doping. Blood doping is withdrawing your own blood and giving it back to yourself before a race to increase red blood cell mass. It is not legal in the sports world.
But running at noon in the heat of the day will induce heat acclimatization, a natural response to training. Running in the heat stimulates your body to produce more oxygen-rich red blood cells. And that will improve your ability to perform well in warm or hot conditions. That is, of course, the purpose of training—and is legal.
If you plan to race in hot conditions, it is critical to have near daily heat exposure while you are training to get your body ready to perform in hot conditions. If you feel it is too hot for you when you arrive at the race site, it may be best not to start or to start at a slow pace and drop out if you do not feel well during the run. It is always better to not start, not finish, or finish slow than to end up in the medical tent or emergency department with exertional heat stroke.
I hope this helps.
I Think I Was On to Something
When it comes down to it, I’ll take the doctor’s explanation of the benefits of running in the summer heat over mine any day. But I still feel that my reasoning is sound.
If your body is making more red blood cells, it is naturally increasing blood volume to deliver more oxygen to your muscles during training while simultaneously allowing ample blood to go to the surface of your body for perspiration and cooling.
And then in the fall, when less sweating is required, there is more blood in total (for a little while at least) to deliver more oxygen to the muscles so they are really able to work at a higher level.
Maybe I’m reading between the lines, but I’m going to say I was at least on the right track.
Keep Running This Summer

Keep Running in the Summer Heat
So this summer, keep running and training at a high level, and you’ll see some serious results for your fall races.
Just make sure you stay safe while you’re training, and remember to be on the lookout (in yourself and in others) for the signs and symptoms of heat injuries, and make sure you take the proper steps to try and limit those risks while still maximizing the training benefits of running in the summer heat.
What’s Your Take on Summer Running? Love It? Hate It? Let Me Know in the Comments!