Why do we slow down when it’s hot?

[030961]

I completed WK7R3 today but went out about an hour after I had planned. It was really quite hot around 10.30 am this morning. It was hard to get to and maintain my usual pace even though that’s usually quite slow anyway. Does anyone know what happens to the body in the heat and what that causes running to be that bit harder? I’m just interested to know what happened to me this morning really so I can try to avoid doing it again in WK8.

[IannodaTruffe Mentor]

Dehydration has a lot to do with it and is explained in this post about hydration healthunlocked.com/couchto5...

[030961 Graduate in reply to IannodaTruffe]

Many thanks IannodaTruffe, very interesting and essential reading I think.

[nowster Graduate]

When you're running you generate a lot of heat. The hotter the environment the harder it is to shed that heat. If the air is also still and humid, sweating as a cooling strategy is less effective too.

Say you run for half an hour and burn 350 Calories doing so: that's the equivalent of an 800W heater.

Drink plenty every day (not just on run days) and avoid running in the hotter part of the day.

[030961 Graduate in reply to nowster]

Very interesting, and wise advice many thanks nowster.

[John_W Graduate Ambassador]

One of the reasons the heart pumps blood around your body is to try keep you cool.

As ambient temperature increases, the heart has to pump more blood around the body in an effort to keep you cool (thermo-regulation and all that) . And as your heart rate increases... we all tend to feel the effects of that... tiredness, slugishness, a greater effort to do normal things etc - your energy stores are being diverted to help the heart pump around more blood than normal.

[030961 Graduate]

Thank you John_W. I’m starting to understand why I get slower in the sunshine. Thank you for getting back, and enjoy the sunshine!