The clear message from over a half a century of
scientific research on the links between food, nutrition and exercise
capacity is that next to natural talent and appropriate training,
carbohydrate ingestion for energy and adequate fluid intake to avoid
dehydration are the two most important elements in the formula for
successful participation in sport.
Dehydration is a major cause of fatigue, poor performance, decreased
coordination and muscle cramping. Proper hydration is extremely
important during exercise. Adequate fluid intake for athletes, even
recreational athletes, is essential to comfort, performance and safety.
The longer and more intensely you exercise, the more
important it is to drink plenty of fluids. Inadequate fluid consumption
can be physically harmful. Consider that a loss of as little as 2% of
one's body weight due to sweating, can lead to a drop in blood volume.
When this occurs, the heart works harder in order to move blood through
the bloodstream. Pre-hydration and re-hydration are vital to
maintaining cardiovascular health, proper body temperature and muscle
function.
Electrolytes are minerals named because of their ability to conduct an
electrical charge when in a solution. Referred to as salts within the
body, electrolytes play a role in conducting nerve impulses, muscle
contractions and are a part of many important physiological functions.
Their primary role is maintaining the delicate fluid balance both inside and outside your body's cells.
Sodium loss has the biggest impact on performance. It's estimated the
average athlete can lose up to 1300mg of sodium for every litre of
sweat. Potassium comes next, followed by Magnesium and Calcium.
However, only a small amount of Magnesium and Calcium are lost in sweat.
Sodium is an essential nutrient, an element the body cannot manufacture
itself. It plays a vital role in regulating many bodily functions and
is contained in body fluids which transport oxygen, carbohydrate and
nutrients. To survive, everyone needs to consume sodium regularly. It
is a principal component of a person's internal environment, the
extracellular fluid. Nutrients reach your body's cells through these
fluids. Sodium facilitates many bodily functions including fluid volume
and acid-base balance.
Sodium enables the
transmission of nerve impulses around the body. It is an electrolyte,
like potassium, calcium and magnesium; it regulates the electrical
charges moving in and out of the cells in the body. It controls your
taste, smell and tactile processes. The presence of sodium ions is
essential for the contraction of muscles, including that largest and
most important muscle, the heart. It is fundamental to the operation of
signals to and from the brain. Without sufficient sodium, your senses
would be dulled and your nerves would not function.
Hyponatremia is a medical condition known as "water intoxication" and is effectively low Sodium levels in the blood, a condition that occurs when heavy sweat loss is experienced during prolonged periods of activity. This is often brought about when someone drinks large amounts of water and/or loses too much salt from the body in a short time. Drinking large amounts of water overwhelms the kidneys and they can't process and eliminate the water fast enough, so the amount of Sodium in your blood drops too low. Your brain also needs Sodium, and when the Sodium levels drop too low, a person will feel confused and lethargic. Severe hyponatremia can also lead to twitching, seizures and even death.