Pro Tip: Dealing With The Heat by Chris McDonald

Pro Tip: Dealing With The Heat by Chris McDonald

As most of us are likely training year round and do not have the ability to escape the summer heat, we all recognize that it is harder to train when it is HOT! The perceived effort is greater, and race and training times typically suffer accordingly. Why does this happen? What happens to the body at a physiological level? Most importantly, how should we adjust workouts and race expectations to best weather the weather?

There are many studies out there that generally recognized that for every 10-degree increase in air temperature above 55 degrees, there's a 1.5 percent to 3 percent increase in average finishing time for a marathon. For an Ironman athlete looking to run a 3:30 marathon, that is 3-6 min. This is compounded even more in my eyes for triathlon as a lot of us are starting the marathon in a more dehydrated state, so I believe it is more like 8-12 min. The slow down occurs because heat impacts athletes at a physiological level through a few different means, including dehydration, increased heart rate and reduced blood flow to the muscles used for running.

Perspiration has a cooling effect on the body because it removes excess heat through evaporation. The rate of evaporation–and subsequently how well the body is cooled–changes depending upon humidity. When humidity is low, evaporation increases and we have a great cooling effect. When humidity is high, the rate of evaporation decreases and the cooling effect decreases.



We can adjust our preparation to become more adjusted to the a humid heat by wearing a cap or long sleeves while training.


When you are heading out into a hot environment adjust your expectations of the work out and be sure to build into the effort so you don't drive your core body temp up to start


Mindset is a huge thing. If you know it is going to be hot and you have don't the steps above, having a positive mindset to deal with things is huge.

If you think it is hot running, go stand in a porto potty for 60 seconds and upon exit it will feel cool! It is all relative

About Chris

Chris McDonald, aka "Big Sexy", is a professional triathlete and 6x Ironman Champion. He also coaches aspiring athletes in Big Sexy Racing. Follow him on Facebook or Twitter @bigsexymcdonald or at


This article was originally published on - August 11, 2014