Six Hydration Mistakes To Avoid On Race Day

…from running.competitor.com

Sports nutrition expert Matt Fitzgerald explains how not to let hydration slow you down.

Written by: Matt Fitzgerald

Every runner knows that hydration is a vital component of performance. At no time is hydration more important to running performance than on race day. Yet race-day hydration mistakes are all too common. Here are the six most common race-day mistakes made by runners and how to avoid making them.

1. Drinking Too Much Before The Race

Some runners think they’re camels. They guzzle water or sports drinks before the start of a race on the assumption that they can store extra water in their bodies and thereby minimize dehydration during the race. But the human body is not designed to do this. Any fluid you consume beyond the amount required to attain normal hydration status will only wind up in your bladder, increasing the likelihood of time-wasting pit stops.

On race morning, drink just enough to satisfy your thirst and don’t drink anything in the last 45 minutes before the gun goes off.

2. Drinking Too Much During The Race

For decades, runners were taught that any amount of dehydration had a negative effect on performance and increased the risk for exertional heat illness, and were told to “drink as much as possible” to completely prevent dehydration. However, the human body was not designed to absorb large amounts of fluid during running. The jostling of the stomach that occurs on the run causes GI distress in runners who try to force down fluid.

What’s more, research has consistently shown that runners perform no worse and have no greater risk for heat illness when they simply drink according to their thirst, even though this typically results in only 65-70 percent replacement of sweat losses. While it is important to drink as often and as much as your thirst dictates during races, it’s a bad idea to drink more.

3. Carrying Your Own Drinks

Have you ever seen a runner win a marathon with a drink belt around his or her waist or a fluid bladder on his or her back? No, and you never will, because it’s a terrible idea. Fluid weighs a lot, and extra weight slows a runner down dramatically. 


Every running event worth participating in provides adequate drinks at aid stations. Use them. Even if the sports drink offered is not your favourite, you will almost certainly perform better by drinking it than you will by schlepping your own preferred beverage.

4. Using A Sports Drink You’ve Never Used Before

Some runners have cast-iron stomachs and can drink almost anything in races. Others have more sensitive stomachs and find that they tolerate some sports drinks better than others. If you are among the latter group, don’t risk finding out the hard way that your stomach can’t tolerate the sports drink available in an important race. Find out what it is and try it in training first.

What should you do if that sports drink upsets your stomach? Your next step is to give it another chance or two and see if it doesn’t become more tolerable over time. This does happen sometimes. If familiarization doesn’t help, then carry gel packets during the race and use them to get the carbs and electrolytes you need. Wash your gels down with water at aid stations to hydrate.

5. Using Caffeine Without A Prior Caffeine Fast

Caffeine boosts endurance performance by affecting brain chemistry in a way that lowers perceived exertion, or how hard it feels to run at a given pace. But it only works in those who are non-habituated to caffeine. If you’re a regular coffee drinker or user of caffeine in other forms, you must go caffeine-free for at least a week before a race to enjoy the performance-enhancing effect of taking caffeine on race morning.

6. Drinking In Race That Last Less Than An Hour

Studies have shown that consuming fluid during race-type efforts does not enhance performance unless the effort lasts longer than about an hour, and in some cases the threshold is as high as 90 minutes. Yet runners routinely drink in 10Ks and other shorter events that they can easily complete in an hour or less. Doing so will only slow you down

About the Author:
Matt Fitzgerald is a regular contributor to competitor.com, Triathlete, Inside Triathlon and Competitor. Matt has written 17 books, and counting, including Brain Training For Runners and Racing Weight.