After a cold and wet spring, we got one of those very hot days that seem to come out of nowhere. It was in the mid 80’s here in Pittsburgh today.  That meant I ran in conditions, that I haven’t experienced since last summer.

I waited until early evening before going for my run. The sun was starting to set, so I hoped that the temperature would be a little more bearable, and that I would find more shade.  This was true, but it was still incredibly hot.

My workout was a 75 minute, easy pace run.  Running at a nice easy effort is tougher when it is hot.  Your body uses energy to keep cool, and so it shouldn’t be surprising that there is less energy for running.  This means that if you truly keep your overall effort level the same, your pace on very hot days, will be slower than cooler days.

That is exactly what happened to me today.  My pace today was about 30 seconds per mile slower, than other similar runs that I have done over the past week or so.  That is 6-7% slower than my ‘normal’ pace.

Oftentimes, athletes try to run at the same pace on all of their long runs.  This can be a mistake on very hot days.  If I had run at my ‘normal’ pace today, I would have run at a much higher effort than was intended.  Doing this once in a while is likely not too bad, but making a habit of it is not.

So next time you run on a very hot day, dial back your pace expectations a little.  It is perfectly fine to train at a slightly slower pace, in situations like this.