Are You Waterlogged?

Water is a hot topic in endurance sports today. It is something I have certainly had on my mind since listening to a podcast with Dr. Tim Noakes. In his latest book, Waterlogged, Dr. Noakes refutes the claims of many juggernaut hydration companies that our bodies require an effort of continued hydration throughout activity in hopes of maintaining pre-race body weight. This is simply not the case. Dr. Noakes goes into extreme depth in his book, and there is no shortage of reviews and interviews that discuss Dr. Noakes' claims, so I will just give you the quick version of what Dr. Noakes is saying. If you desire a more in-depth explanation, follow the links at the end of this post.

Dr. Noakes asserts that the human body has an incredible ability to survive in what we might consider quite dire situations. He has calculated that, unless participating in multi-day endurance activities, our body stores enough sodium to make supplementation during a race unnecessary (assuming the athlete's diet is adequate in sodium). 

Granted, it has also been shown that taking sodium tablets can have a placebo effect on performance if you are convinced they are going to improve your performance. So don’t throw away your S-Caps quite yet! As long as you aren’t taking in so much sodium that your body is swelling up and carrying extra water, there really is no harm in continuing your typical sodium fueling routine.

The main problem Dr. Noakes addresses is hyponatremia, a condition that arises when the sodium concentration in the blood is too low. Symptoms often include vomiting, headache and—in extreme cases—even death. Popular wisdom says this is a result of a sodium deficiency, but Dr. Noakes demonstrates that athletes often suffer hyponatremia because they have taken in so much water (or sports drink) that the sodium in the body becomes so diluted that the body thinks there's a deficiency. Athletes sometimes mistake the symptoms of hyponatremia for dehydration and subsequently take in more water, making the condition even worse (sometimes at the urging of aid station volunteers, who also read the symptoms as signs of dehydration!).

What to do? Well, don’t freak out about this and refuse to drink any water during your next endurance event. Dr. Noakes emphasizes that you still need to drink, just not in excess. So what is the ideal amount? The body is amazing: It will tell you when it is thirsty. Drinking to thirst is adequate in endurance athletics. Just listen to your body’s signals along the way. 

Also note that many athletes finish endurance races under pre-race weight. One study Dr. Noakes did was testing the rates of weight lost throughout endurance activities. He found it interesting that many of the top finishers were the ones who lost the highest percentage of body weight through fluid loss (see the study on Runner’s World about elite marathoners losing lots of water). A particular interesting example was Haile Gebrselassie’s Berlin Marathon in 2008, where he broke 2:04. He was reported to have lost up to 10 percent of his body weight over the course of the race. Obviously, he spent the rest of the day balancing that back out, but this information is interesting to see in a time when we are being encouraged to drink so much that our weight doesn’t change during races. 

One must keep in mind that weight lost during an endurance activity is not directly associated with just water. For every gram of carbohydrate your body stores as glycogen, nearly 3 grams of water are stored with it. This means if you rifle through your glycogen stores and finish depleted, you will have lost weight simply because your body has less glycogen on board. This will also rebalance as you refuel post-race.

I would love to hear personal experiences, opinions, or wonderments on this topic. Please post how you feel about this.

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For More Information

• iRunFar.com Article by Joe Uhan on Waterlogged
• Ben Greenfield interviews Dr. Tim Noakeson his podcast