Is the heat making you less fit?

So I don’t know about you, but I am running at least 1:00-1:30 min/mile slower than I was in the early spring when the temperature was considerably cooler.  I wasn’t sure if it was the heat, the fact that I have gained some weight (some muscle and some fat), or my body getting more fatigued as I progressed in my Half Marathon Training.  I recently ran across an article from Runner’s World, “What Pace Should I Run in the Heat?” by Susan Paul. 

According to the article, the heat can raise your heart rate 20 bpm while doing the same level of activity.  That is part of what makes running the same pace as you would in cooler weather so uncomfortable.  Susan says you should typically slow down 30-90 seconds per mile.  I know that I don’t want to lose all of the gains that I made over the winter.  What does that do to your overall endurance? 

There is some good news.  While you are running slower, your heart rate is not lower, and is sometimes higher than it was in the cooler weather.  While many of us equate pace to how well your training is going, it is your heart rate that measures your overall condition.  If you are pushing the same heart rate or higher than you were in the cooler weather, it will benefit you when the weather changes again.  Susan says it will feel like you have lost 10-20 pounds instantly and you will easily be able to achieve the pace you were running at before. 

One thing to take into consideration is that while you are running at a slower pace, your body might need some different types of runs to make up for the lack of speed.  Different muscle fibers might not get worked and workouts like Fartleks, Intervals, Hill Workouts, and Tempo Runs can be sprinkled into your normal training schedule to make up for the slower speeds. 

Don’t worry if you have to slow down a bit because of the heat.  Just focus on your heart rate and know that when the cooler temperatures return, you will be able to kill it!  In the meantime, try to run in the morning or evening when it is not quite as hot out.  Now get out there and enjoy the day!

Sources:

(1) Susan Paul, Runner’s World, “What Pace Should I Run in the Heat?” August 27, 2013, http://www.runnersworld.com/for-beginners-only/what-pace-should-i-run-in-the-heat

Picture Sources:

http://www.thecompleterunner.com/wp-content/uploads/Running-in-the-Heat.jpg

http://www.active.com/Assets/Running/580/heat-related-illness-580.jpg