Dehydration and Sport Performance

Staying hydrated in the Texas summer heat is very important for sport performance. There have been numerous studies on the effects of dehydration and exercise.  Most experts agree that 2% dehydration will lead to a drop in sport performance of up to 21%.  Furthermore, a decline in cognitive function occurs at 2% dehydration including skill sports such as soccer.

There are several reasons for the drop in production.  As you start to dehydrate, there is a decrease in plasma volume.  This causes a decrease in stroke volume and a decrease in skin blood flow.  With less blood going to the skin, it becomes harder to sweat and cool your body.  Ultimately, your core temperature rises which begins to take a toll on your body which may cause cramping and heat exhaustion.

I've seen several people wearing extra clothes or "sweat" suits to try and lose more weight.  The truth is, those people will lose more weight BUT it is mostly water weight which returns as soon as they are properly hydrated.  Instead of focusing on weight loss for the afternoon, focus on performance and intensity.  Proper exercise will benefit you more in the long run than "sweating" out a few extra water pounds.

Therefore, expert recommend properly hydrating yourself before your activity.  Drink at least 4 liters of water 24 hours before your activity if not every day.  Drink another ½ liter 1 to 2 hours before your event.  Then drink plenty of fluid during your activity and include a sport drink if you are exercising for more than 1 hour to replace any electrolytes lost in the sweat during your activity.