Fluid Replacement

By Ian Turlington

During prolonged running the bodies internal temperature rises which leads to Decreased Stroke Volume (amount of blood pumped out of the heart with each beat) increased Heart Rate (number of heart beats per minute) decreased Cardiac Output (total amount of blood pumped out of the heart each minute), and a decreased in blood volume. The above factors all decreased the bodies ability to deliver oxygen to the working muscles, which has a major negative effect on endurance performance, as the muscles need oxygen to produce energy aerobically.

It is therefore very important to slow down increases in internal body temperature as much as possible. During exercise more than 60% of the bodies heat is lost through evaporation from the outer surface of the body. Excess heat produced from energy production is transported by blood to the surface of the body and is sweated to the skin and is then evaporated.

As a great deal of water is being sweated out of the body during intense exercise, water loss occurs and the bodies ability to dissipate heat is reduced resulting in increased body temperatures.

The main part of this article is the importance of fluid intake before training and races and fluid replacement after training and races. Several studies have shown that dehydration can result in a 20% decrease in endurance performance, so it is therefore vital that sufficient water replacement takes place before and after training and racing. This does not mean gulping down 2 litres of water before a race (as this will result in stomach problems - decreased performance) but a controlled intake of fluids in the hours leading up to races.

There are many fluid intake techniques used to elite athletes which can be found in sports science books, on the internet or from your coach.

I hope that this be be of use to some athletes and if anyone had any more ideas on pre-race fluid intake techniques then I would be very grateful to hear them.

It must be stated that this is not going to turn you into a world beater over night (because its hard work and determination that's going to do that) but it will form part of the overall process of being the best prepared as possible!!

"On the race day its not always the most talented athlete that will come out on top, but being the best prepared will go a long way to surpassing your individual goals"