Wednesday, March 14, 2007

A Visit from our Resident Science Geek

Hewsflash: Being an Old Salt Could Help Your Racing!

This week I am going to address sodium. To do this I will borrow heavily from a paper written by Michael F. Bergeron, Ph.D., FACSM. The full paper can be found here.

When I started racing, I was told that potassium is the big electrolyte needed for preventing cramps. Eat your bananas, drink your orange juice, etc. I now know sodium is typically the culprit when cramping is the result of an electrolyte imbalance.

Your Morton's salt gal might be a better companion than the Chiquita Banana Lady in terms of keeping you in top racing form. Read on to find out more.

Here are some key points from the paper:

1. Athletes lose far more sodium and chloride in sweat than any other electrolytes.
2. Sodium and chloride losses are greater with higher sweating rates.
3. Sodium and chloride losses in sweat are usually less when an athlete is acclimatized to the heat.
4. To completely replace body fluids after exercise, an athlete must replace the sodium and chloride that were lost through sweating.
5. Sodium deficits can lead to incomplete rehydration and muscle cramps.

Previously I talked about sweat rates and hydration. Since sodium is lost in sweat, knowing your sweat rate will also help you learn to "dial" in your sodium needs. A good place to start is 1g sodium lost per liter of sweat. For some unacclimatized athletes exercising in the heat, losses can be as high as 2 grams per liter of sweat.
Every athlete is different, so practice with your training and figure out what works best for you. Dr. Bergeron's paper has some good information and links in it, so check it out. It is a good exercise in reading technical papers; A skill that can open up many new doors for getting your nutritional edge over the competition.

Happy training (and reading)


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