And how to get the most out of your summer training.
Before diving into the topic of heat adjusting your running paces, let’s start with a quiz.
What feels easier: running 10-minute miles in 55°F or 85°F?
If you’re like most people, you probably said the first option—and with good reason. Same pace, but completely different conditions. Running in the heat simply feels harder.
Reduced blood flow to the working muscles means less oxygen delivery, more cardiovascular strain, and a higher heart rate at any given pace. And when your heart is working harder, your perceived effort goes up—even if your pace stays the same.
When it’s hot out, your body goes into “survival mode”, so to speak. To keep your core temperature in check, your body redirects blood flow toward your skin to help you cool down through sweating. But here’s the catch: that blood has to come from somewhere. In this case, the body redirects some blood away from your working muscles and towards the skin.
What Happens When You Don’t Heat Adjust Your Running Paces?
Trying to force your usual pace—whether that’s easy pace, marathon pace, tempo, or anything in between—on a hot, humid day can lead to burnout, dehydration, or worse, heat-related illness.
Even if you manage to push through and run your normal paces, you’re not training smart.
Ever heard the expression “Just because you can, doesn’t mean you should?” That’s especially true in this scenario.
Pushing through without adjusting for the heat might feel like a win in the moment, but it comes with a cost. Recovery gets harder, progress slows, and you risk burning yourself out.
Why Is Heat Adjusting a Smart Strategy?
Heat adjusting your running paces isn’t a sign of weakness. On the contrary, it’s a sign of maturity as an athlete. While it may mean putting your ego on the shelf and slowing down in the heat, it also shows that you’re more in tune with your body and the conditions you’re running in.
Many experienced athletes use pace adjustment charts or calculators (such as VDOT) to determine how to heat-adjust their running paces in warmer conditions. The higher the temperature and humidity, the greater the adjustment.
How to Heat Adjust Your Running Paces
- Use perceived effort. Focus more on how the effort feels rather than what the pace says. Don’t stress if you’re a few seconds slower than your normal tempo pace, so long as you feel like you’re running tempo effort.
- Listen to your body. If your heart rate and breathing feel more elevated than usual, take a log off the fire and slow down the pace a bit.
- Hydrate more frequently. Be proactive rather than reactive. Don’t wait until you’re thirsty to hydrate. Hydrate early and often during warmer conditions.
- Extend your recoveries. Warm temperatures place extra strain on your body, so don’t be afraid to take more rest between intervals or sets.
The Big Picture
You’re not weak for slowing down in the heat—you’re wise. Trust your coach, trust the process, and trust that showing patience now will lead to performance later.
Elaina Raponi is a coach with Team RunRun based in Kingston, Ontario. Elaina loves helping athletes of all abilities and experience levels achieve their goals, while finding confidence and joy in the process!