The importance of hydration

Many athletes routinely travel abroad to warmer climates for training camps or races. For many the reason for travelling is very important and is often the culmination of a lot of training and hard work. It is a shame however that many athletes under perform due to something as simple as drinking.

Scientific studies have shown that as little as a 1.5% drop in hydration negatively affects performance. Many athletes over the course of an Olympic distance triathlon will lose in excess of 5%.

Water is essential as it provides the body with it cooling mechanism (sweating). As the water on the skin evaporates it cools the skin and therefore the body. If you stop sweating (due to dehydration) the body can no longer cool itself and core body temperature will rise.

Sports Scientists have a range of methods both blood and urinary that can assess an athletes current hydration status. Usually this involves fairly expensive and cumbersome equipment not available to most. A very common method for athletes to easily assess for themselves is to use a urine colour chart like the one below. The procedure is very easy, simply compare the colour of your urine to the colour and corresponding number from the chart below.

1 - 3 = Optimally Hydrated

4 - 6 = Slightly dehydrated should drink more

6 - 8 = Dehydrated, must drink more

As an athlete you should aim to be optimally hydrated at all times (1-3) on the chart.

In a hot environment it is not unusual for an athlete to lose 2-3L per hour. In more temperate conditions the sweat loss is more likely to be 1-2L per hour. Men tend to lose more sweat than women due to their size. As a coach an easy way to find out how much fluid your athletes have lost in a session is to weigh yourself (and any water bottles you will drink from), before and after a workout. The difference between the two will be the amount of fluid you need to replace. Bear in mind that 1L of water weighs 1Kg, therefore a 1.5kg drop in body mass in a session equates to a fluid loss of 1.5L.

As odd as it may sound over drinking is a very common problem particularly in endurance athletes who are very concerned about their hydration. The problem of over drinking is that you dilute the electrolyte (body minerals and salts) concentrations in the blood. Electrolytes are used by the body for a variety of functions including muscle contraction. Ironically the symptoms of over hydration are very similar to those of dehydration (headache, cramping, nausea). In order to avoid this situation, adding electrolyte to your athletes fluid intake will assist in helping them in maintaining a normal electrolyte balance.

It has been repeatedly demonstrated that sipping fluid over a long period of time is much more efficient in terms of rehydration than consuming large volumes quickly. The sipping over time method allows the water to be uptaken by the cells where it is needed.