Salt in its natural mineral form is one of the oldest known diet supplements. Salt was used by laborers in warm, heavy industrial environments of North America in the late 1800s. Sodium is lost in the body during prolonged exercise through perspiration and urine excretion. Sodium can only be replaced through dietary sources or supplements.
In warm weather, the amount of sodium that an athlete may lose through perspiration is varied. A typical adult athlete will lose sodium at a rate between 100mg and 700 mg per liter, and will lose perspiration between 1 - 2.5 liters per hour. The consumption of commercial sport drinks is not necessarily a solution to sodium deficit. To achieve sodium replacement through the sports drink, the formulation would have to taste more like seawater than a sweetened beverage.
Salt tablets present problems for athletes if taken orally to correct sodium deficiencies. In their raw form, salt tablets are often difficult to digest, causing gastric irritation, with accompanying nausea and diarrhea a common side effect. The stomach has difficulty in the immediate digestion of salt tablets, meaning that the benefit of the sodium is delayed; sports drinks, and their nutrients, are far easier for the body to absorb. Swallowed alone, without significant fluid to accompany the salt tablet, the sodium will act to further accelerate the dehydration of the body.
Some of the best hydration strategies are:
- Hydrate daily: The body performs best when the athlete is already engaged in day to day hydration practices. This includes regular water consumption through the course of each day.
- Pre-hydration: The athlete consumes 16 oz. of water approximately two hours before the start of the session.
- Event hydration: In short distance races, an athlete may only consume fluids at one interval but in distance events it is recommended for athletes to seek fluids every 1-2 minutes, in quantities of 4-16 oz.
Strategies to Meet Your Hydration Needs:
- Plan for and practice fluid intake during training.
- Always carry fluids with you.
- Know the capacity of your water bottles and know how many times you need to refill them to meet your needs.
- Know the warning signs of dehydration: unusual fatigue, lightheadedness, headache, dark urine, and dry mouth.
- Be aware of hyponatremia (low blood sodium levels). Symptoms include lethargy, muscle cramping, mental confusion and seizures. Electrolytes must be replaced, especially for events lasting longer than 90 minutes.
- Drink by schedule, not by thirst. If you feel thirsty you are already dehydrated.
- Pouring water over your head does not lower body temperature.
- Sports drinks may be used to meet fluid, electrolyte and carbohydrate needs during exercise. These beverages contain calories and should not be consumed in excess.
Food as Hydration
Food, often overlooked as a water source, can be a rich supply of fluid. On average, it provides 20 percent of the fluid we take in on a normal basis. Some of the best foods to hydrate daily with are fresh, juicy fruits, such as, apples, kiwi, watermelon, grapefruit, coconut, strawberries, berries, raw, green vegetables, such as bok choy, celery, escarole, spinach, cabbage, and broccoli, lastly water based, clear soups such as a vegetable soup.
Successful hydration requires a measure of planning. The development of a hydration strategy will depend on the nature of the event, the anticipated weather conditions, the outcome of any acclimatization to either heat or altitude that the athlete has been subjected as part of training, and the physical attributes of the athlete.race near you.