Hydration and Heat

Take it from a girl who spent 8 years running in the jungle.   Heat can really take it out of you.  As the summer days warm up you begin setting your alarm clock earlier and earlier to to beat the heat.  All too quickly you realize there’s just no beating it.   Come mid summer even the most disciplined runners, meeting up with their running buddies at 5:00 a.m., come back from their runs soaked in sweat.  Since there seems to be no way around running in the heat in the South we need to know how heat effects our runs and what to do about it.

No question about it, heat and humidity take it out of you.   This is why afternoon siestas are so popular in tropical countries.   Our bodies slow down in extreme heat.   The same is true with running.   Running Times magazine stated that  just 3% dehydration is equivalent to a 8% loss of speed.   That’s Huge!

Let’s look at the three main effects heat has on our running performance.

  1. Dehydration and sodium loss
  2. Increased Heart Rate
  3. Body temperature increase

As we become dehydrated our blood becomes thicker and our blood volume drops.  This causes our heart to work harder and beat faster.   Also, blood that is normally channeled to the primary running muscles is now diverted to the skin to cool our body temperature.   Our heart works overtime and our running muscles are not getting the blood they need to work to their full potential.   The result?  Our performance plummets.

The good news is our bodies have the amazing ability to acclimate to the heat.  But you need to give your bodies the time they need to adjust.  Remember how the participants suffered in the  2012 Boston marathon?  The early spring freak heat wave caused the winning times to be close to 5 minutes off normal! The athletes weren’t acclimated to the heat that early in the season.  Given a little time not only do our bodies acclimate they also become stronger and more efficient at absorbing fluid, metabolizing, cooling the body, and flushing out lactate!

As well as drinking liquids before, during and after workouts we need to be drinking water all day.   A good rule of thumb for athletes is to drink 1/2 -1 oz of water per pound of body weight.   For example a 120 pound runner should aim to drink between 60-120 oz of water per day.   When the temperature and mileage is up you need to be drinking closer to high side of this recommendation.

Be careful out there hydrate.  Your performance depends on it.

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