Salt Ingestion Protocol

By Max Wunderle

No matter the activity one is engaging in along the path to endurance racing, each effort can be distilled down to one of three paths, training, fueling and recovery, period.  No matter what element you may be discussing, each can be bucketed into one of these three vital channels of preparation.  Furthermore, a lack of attention to any one of these three avenues will sub optimize one’s results.  The most aggressive, dedicated athlete can go out and work as hard as possible, but if their recovery and fueling strategies are wrong, such efforts will be wasted.  Similarly, if one’s nutrition and recovery strategies are solid, but one’s efforts aren’t at the proper intensity levels, results will be compromised.

This article will seek to break down and simplify a sub category of nutrition protocol, salt ingestion.  On race day (and in any efforts lasting longer than 1.5-2 hours) one must be actively aware of three areas that must be tended to.  These areas are caloric fuel replenishment, hydration and salt/electrolyte replacement. 

The rule of thumb for caloric fuel replenishment calls for a fueling strategy that delivers approximately 300 calories per hour (this number may be varied depending on body size and effort level).  This strategy is best executed through eating approximately 100 calories every 20 minutes for the duration of the event.

From a hydration perspective, minimum target consumption of water should be about 16 oz per hour.  This number, however, can sway wildly in more aggressive conditions.  For example, if a 170 lb male is competing/training in a relatively low humidity environment at 73-76 degrees, the 16-20 oz per hour target is quite sufficient to ensure optimal hydration levels.  Conversely, as the temperature goes up, say 85 degrees with increased levels of humidity, the target consumption levels of water can be as high as 32 oz per hour.  To experiment with various activities and temperature environments, please visit the Gatorade hydration calculator at http://www.gatorade.co.uk/. 

The third element of race/training fueling is electrolyte/salt replacement.  In essence, the need of electrolytes (primarily sodium, potassium, magnesium, calcium and chloride) is vital to optimal body function.  If optimal levels of electrolytes are not maintained, athletes can fall into a state called hyponatremia, a condition that is defined by low sodium levels in the blood.  Symptoms of this state are weakness, cramping, nausea, fatigue and vomiting.  Ultimately, this condition can even cause death as it has in several marathons over the past 3 years.  In each case of death (Chicago and Boston marathons), the athletes in question consumed vastly gluttonous amounts of water that effectively diluted their electrolyte levels and brought on hyponatremia. 

To best identify your needs around hydration, we simply need to understand the amount of fluid being lost in any given hour of exercise.  To do this, weigh yourself (without workout clothes on) before your session, then do the same afterwards.  If you consumed fluids during the session, simply subtract that weight (roughly 20 oz of fluid per lb) from your post workout result.

Once you know the amount of fluid you are shedding per hour, you can then estimate losses of various electrolytes in the following amounts.  I’ve also included an electrolyte breakdown of a TriMax partner electrolyte replacement product, Saltstick.

Comparison of Electrolyte Content and Cost of Common Electrolyte Supplements

From Maughan and Shirreffs, 1998. Fluid and electrolyte loss and replacement in exercise. In Oxford textbook of sports medicine, 2nd Edition. Edited by Harris, Williams, Stanish, and Micheli. New York: Oxford University Press, pp. 97-113

Now that you know your sweat rate, you can plan your training and racing activities appropriately.  As an example, if you are sweating about 22 oz per hour of fluid, you now know that you need to replace about 440 mg of sodium every hour to retain optimal performance.  Before jumping into an electrolyte/sodium replacement supplement, you must back out the electrolytes present in your calorie source (gels, bars, etc.).  So, if you are using GU Energy brand gels, each pouch contains about 55 mg of sodium.  Based on consuming 3 gels per hour, your nutrition source will be doubling as a sodium replacement source as well, but will come up short by about 275 mg.  Therefore, the use of an electrolyte replacement capsule like Saltstick (1-2 capsules per hour) will be needed to fuel this hypothetical athlete with a sweat rate of 22 oz per hour.

Happy training!

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