Sweat does have salt in it; however, you do not need to ingest salt tablets after working out vigorously.  Even sweating 1 to 3 quarts per hour of exercise would not require extra salt.  In addition, if you train hard on a regular basis, you are not likely to develop a salt deficiency even with high sweat rates on hot days.  Training promotes changes in the body that conserves salt.

Athletes need to be concerned about adequate salt intake.  Examples of the types of athletes who do need to be concerned about adequate salt intake include:

• American football athletes
• Ultra marathon athletes

The danger for these types of athletes is low body sodium levels (i.e., hyponatremia).  When water or other low-sodium beverages are consumed in high quantities, a loss of sodium in the sweat can cause the sodium level to fall too low.  This condition causes symptoms similar to heat illness.  The symptoms include:

• Fatigue
• Light-headedness
• Weakness
• Cramping
• Weight gain
• Nausea
• Bloating and/or swelling
• Dizziness
• Headache
• Confusion
• Fainting
• Disorientation
• Seizures or coma (in severe cases)

For most other hard-working exercisers, hyponatremia is not normally a great concern.

Most sports drink beverages contain small amounts of sodium to enhance palatability or the taste, which helps individuals take in more fluids during and after workouts.  Another advantage of beverages with a little sodium is less urination than plain water.  Sodium in sports drinks does not enhance intestinal fluid absorption in most people with an adequate dietary intake nor do they improve endurance performances.

A greater issue for most adults is excessive diet salt intake.  Sodium is an essential mineral.  The body needs approximately 500 mg of sodium per day.  Most Americans consume a lot more than this, usually around 4,000 to 6,000 mg per day.

High sodium intake is associated with high blood pressure and a factor for myocardial infarction and strokes.

The United States Department of Agriculture recommends sodium intake for young adults be limited to no more than 2,300 mg per day.  This is the equivalent of a little more than a teaspoon of table salt.   The following groups of people should consume even less than 1,500 mg of sodium per day:

• Older individuals
• African Americans
• People with chronic disease like hypertension, diabetes and kidney disease

When it comes to sodium intake and the worry of a sodium deficiency, most people, even fitness enthusiasts, should not be concerned.  The concern lies within “too much sodium.”  The exception to this rule is if you are an athlete such as an American football player, or an ultra marathon runner.

Source: ACSM’s Health and Fitness Journal, May/June 2007