How dew point affects training

We all know when it gets really hot perceived exertion is higher.
And people say, “Wow, the humidity really got to me today!”

But did you know there’s a hidden element to the weather that few people notice but can have an even bigger impact on your training and racing effort level? 

That’s right, it’s the dew point. So let’s overly simplify a rather complex scientific topic!

What is dew point?

I’m gonna try to not get too technical, but the dew point is the temperature at which dew begins to form. That’s the dumbed down version of the meteorological definition. 

When dew point and temperature are the same, the air is 100% saturated. 

What does dew point have to do with training and racing?

Here’s the deal, the higher the dew point in the summer the harder it is for water to evaporate. Because when dew point and temperature are closer the air is “thicker” with water.

And what’s the primary cooling mechanism for the body? It’s not just sweating, but the evaporation of sweat off the body. 

Higher dew point, especially when the temperature is high, means the sweat your body is producing has a hard time evaporating, which means your body isn’t cooling as it should.

This is where the “feels like” temperature comes from! 

What to do about the dew point?

While it might be out of the norm to start checking the dew point compared to the temperature, or even the humidity, the dew point will more than likely play a bigger role in your perceived effort. 

If you want to start looking at dew point, here’s a rule of thumb. 

Less than 59: Probably gonna want to go for that PR.
60-69: This is where things start to get a little harder. It’d be good to adjust expectations and slow down in the higher range.
70-74: Expect to suffer, adjust your goals to be slower. You’re gonna feel it.
75+: Drastically adjust your expectations, if it’s a key session it might be best to take it inside. If inside isn’t an option it might even be wise to cut it. 

What about you? Have you ever looked at dew point before? We’d love to hear how you’ve found it affecting your training and racing.