However, individuals who are avid exercisers that not only exercise at a high intensity but also in the heat may actually need salt in their diet. Heavy sweating during exercise combined with heat exposure commonly produces fluid deficits corresponding to 1-8% loss in body mass.
Two things can happen to athletes under such conditions of high heat and heavy sweating.
1) Hyponatremia (decreased sodium in the blood)
2) Lack of proper hydration
Over the last 20 years, it was recommended for endurance athletes to consume as much fluid as possible before, during, and after exercise. Unfortunately, these recommendations caused many athletes to become hyponatremic. Hyponatremia is caused when individuals over-ingest water during exercise lasting more than 4 hours. It is not likely to be a major risk factor for the general population. However, precaution should be taken for those individuals that are ultra-endurance athletes, people with occupational physically active jobs, and prolonged heat exposure while being physically active.
LACK OF PROPER HYDRATION
The thought use to be that exercise leads to sodium losses and heat cramps. Research, however, refuted this argument to find that the main nutrient lost during heavy sweating is WATER. Sweating during high intensity athletic events may cause an individual to lose up to 3 liters per hour under hot and humid conditions. In knowing this, recent studies have shown that when water is consumed, the volume ingested needs to exceed the fluid deficit by approximately 150%. This means an individual needs to drink 4.5 liters of water per hour of exercise done needs to help compensate for sweat and uninary losses.
When it comes to the consumption of Sports Drinks, its best to avoid when exercise lasts less than an hour and is not continuous exercise in a hot and humid environment. Reason for this is that nobody needs the extra calories from the sugar put into these drinks. Additionally, if an individual consumes a well balanced diet, the added electrolytes may not entirely help you but rather, you will dispose of the electrolytes through your urine.
However, inclusion of sodium and other electrolytes in the form of sports drink, may be consumed when an individual is doing continuous, high intense exercise for over an hour. The purpose of Sports Drinks are to help rehydrate an individuals body quickly and help to improve performance and productivity. This is accomplished through a well balanced mix of water, sugar (carbohydrates), and salts (electrolytes).
To recap: Drink water first, and sports drinks second!
Sodium-Salt-Needed for Ultra-Endurance Athletes
By Elizabeth Quinn
Role of Sodium in Fluid Homeostasis
By: Rick L. Sharp
J Am Coll Nutr