Even if you have never had a “cramping problem” in the past, neglecting electrolytes in training and racing could be compromising your results. Just like you wouldn’t wait until you were dehydrated to drink fluids, waiting until that first “cramp” is a signal from your body that your performance has been suffering for quite some time. Electrolytes play a crucial role in muscle function, adequate hydration status and digestion fluids during racing.
What is an electrolyte?
In medical or scientific terms, an electrolyte is “any compound that, in solution or in molten form, conducts electricity and is decomposed (electrolyzed) by it. It is an ionizable substance in solution.”
In other words, it’s a term for minerals that, when dissolved in water, break into positive or negative electrically-charged ions (anions or cations).
What are the functions of electrolytes?
Do you take electrolyte supplements before or after your run?
These ions carry electrical energy necessary for many functions in the human body, and optimal athletic performance requires adequate (and a consistent) supply of electrolytes. These ions move across membranes carrying fluids, nutrients and water. They aid in a number of processes that are important to an athlete:
- Regulation of body fluids
- Transmission of nerve impulses
- Muscle contraction (including the heart)
However, repeated days of moderate or severe sweating can result in such substantial electrolyte loss, particularly sodium because of its high concentration of this mineral in sweat. When electrolytes are lost too quickly, the body does not have the ability to restore them as rapidly as they were lost. In these situations, dietary mineral intake is generally not sufficient to compensate for these large losses, and supplementation is needed to replace these electrolytes in order to maintain concentrations of body fluids.
What are the major electrolytes in the body and what do they do?
- Potassium (K+) – regulates heartbeat and muscle function
- Magnesium (Mg2+) – aids in muscle relaxation
- Sodium (Na+) – regulates total amount of water in the body
- Calcium (Ca2+) – aids in muscle contraction
- Chloride (Cl-) – helps maintain a normal balance of body fluids
How are electrolytes lost?
Electrolytes are lost through urine and sweat. Endurance athletes can lose large volumes of sweat on a daily basis, which is accompanied by a similarly large electrolyte loss.
Each athlete has different electrolyte (and fluid) needs and environmental conditions of training and racing will factor into this.
Average sweat rate is typically 1 – 1.5L of fluid per hour (32 – 48 oz.) and 1,000 – 1,500 mg of sodium per hour while running (a bit less when cycling).
Most people’s sweat contains about 500mg of sodium per 16oz. Very salty sweaters can have up to about 1,500 mg per 16 oz. of sweat.
Sweat rate will depend on several factors including environmental conditions (temperature, humidity), genetics and the athletic fitness of the athlete.