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Proper Hydration in Sport

Hydration status of an athlete is one of the most important if not the most important factors affecting overall athletic and mental performance. Research shows that mental cognition and physical attributes such as strength, power and endurance all decrease. Dehydration can occur through a number of ways such as exercising in hot, humid conditions, inadequate fluid intake, sweating, expiration, which can in turn lead to further medical complications such as heat exhaustion, heat stroke, heat/muscle cramps and ... alternate complications such as cooking of the hypothalamus and possible a coma leading to death.

Athletes are generally aware of hydration issues on the day of the race/event. However the hydration process needs to be started early. There are a number of ways to prevent dehydration, such as to drink adequate fluids pre-event (3-4 days leading up to the event), preferably water and other drinks that contain electrolytes such as sodium and potassium. Research has shown that athletes competing longer than 6-8 hours may need up to 1 gram of sodium per hour to replace losses. Some of this can be replaced by using generic sports drinks before and during the event. There are a number of nutrients that are important in a hydration drink. The most obvious ones are Potassium and Sodium.

Sodium is an electrolyte in the body. It is required in the manufacture of hydrochloric acid in the stomach and can help protect the body from any infections that may be present in food. It also assists in preventing muscle weakness. Sodium is also important in increasing blood plasma volume (dehydration is associated with a decrease in blood plasma).

Potassium is needed for growth, building muscles, transmission of nerve impulses, heart activity to name a few. Together with sodium - potassium inside the cell and sodium in the fluid surrounding the cell, work together for the nervous system to transmit messages as well as regulating the contraction of muscles. It also helps prevent fatigue, cramping and muscle weakness. It should be noted perspiration increases the body's use of and need for potassium.

Glycine is also another important ingredient in a hydration drink. It is required for building protein in the body, aiding in the absorption of calcium in the body and helps to slow down muscle degeneration by supplying additional 'naturally occurring' Creatine in the body.

Taurine allows the body to absorb and use potassium, calcium and sodium. It assists in more efficient fat metabolism and has an insulin mimicking property which helps shuttle nutrients into cells.

Magnesium always gets a lot of attention. It helps with formation of bone and teeth and assists the absorption of calcium and potassium. It helps to relax muscles, reducing the likelihood of cramps and twitches and is required for cellular energy production. Magnesium has been reported to reduce the incidence of some stress-related health problems. It should be noted that perspiration increases the body's use of and need for magnesium.

As an athlete you should remember that when you are 2% dehydrated, you work at 90% of your maximal capacity (Saeed, 2003). Hence you need to begin your hydration early. Below you will find hydration guidelines for training an event such as Ironman before, during, and after the event; however they can vary due to a change in environmental conditions.

Normal Training Day

Approx. 4.5 litres to 5 litres per day (EcoAde during training)

Event Day

Pre-event:

2 hours pre race: 750 mls to 1.5 litres (Sip on EcoAde hours prior to race, 15-20 mins pre race: 350 mls to 500 mls.

During event:

700mls to 3 litres per hour (hot humid conditions require @ least 1 bottle of EcoAde/hr).

Post Event:

2 x 750 ml Water Bottles (@ least 1 being EcoAde) within the first 2 hours or 1-2 litres per 1kg body weight lost.

This obviously has certain implications and is only a very rough guide because in fact a person in hot humid conditions can loose between 1 and 4 litres per hour. A more accurate guide will come after you have trained and competed in a variety of weather conditions. A way to monitor fluid loss is to record your weight before and after an event and monitor what and how much fluid you've consumed. One of the best ways to evaluate your hydration status is through weight (1 litre is equivalent to 1 kilogram, Each liter of sweat dissipates about 600 calories of heat, preventing a rise in body temperature of almost 10° C.) and/or monitoring the color and quantity of urination.

A condition you should be aware of is 'Hyponatremia'. Hyponatremia is a condition known as 'water intoxication' or 'over-hydration.' It is the opposite of dehydration, and is often associated with long distance events like running and cycling. Over-hydration usually occurs when an athlete is performing in hot humid conditions, where they sweat profusely, and is replacing lost fluids with plain water.

It is a condition whereby the concentration of salt in the blood becomes diluted. Hence electrolytes become depleted (also through sweating) which then similar to dehydration begins to interfere with the function of the brain and skeletal muscles.

So next time you train or compete not only be aware of the importance of hydration, go the extra mile and plan your hydration and monitor and record your hydration status. Remember trial and error so trial your consumption during a race to help provide you with the winning formula for the race day.

Spirts, D. BSC