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 compounding even more in my eyes for in triathlon as a lot
of us are starting the Marathon in a more dehydrated state and 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 affect when humidity is high,
the rate of evaporation decreases and the cooling affect decreases.
WHAT TO DO?
1) ADJUST YOUR PREPARATION.
We can adjust our preparation to become more adjusted to the
humid heat by wearing a cap or long sleeves while training
2) ADJUST YOUR EXPECTATIONS.
When you are heading out into a Hot environment adjust our
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
3) ADJUST YOUR MINDSET.
Mind set is a huge thing. If you know it is going to be hot and
you don't have
the above steps, having a positive mindset to deal with things is huge.
If you think it is hot running go stand in a port-o-potty for 60 sec. upon exit it will feel cool! It is all
relative :)
See you at the races!
Chris McDonald, 6x Ironman Champion