Playing in the Heat

Beach Tennis players are particularly at riskas the game is usually played outside, in the summer months of the year, in the intense heat of the sun.

Human body

The human body is like an efficient thermostat, and most of the time we pay no more attention to its activity than we do to our central heating system at home.

When the outside temperature threatens to lower the body's core temperature below a certain level, the body kicks in with a number of measures that are designed to reduce heat loss.

When the outside temperature threatens to raise the core temperature, the body triggers a number of other measures to lose heat, like sweating and opening up all the blood vessels near the skin (which is why you go red).

However, when you exercise for a long time in hot conditions - and especially in high levels of humidity - you put a lot of pressure on your body's thermostat, and there is a very real danger of overloading it.

Tips on keeping cool

Take extra care on hot, humid and sunny days. Avoid unnecessary exercise during the hottest hours of the day (usually between 1000 hours and 1500 hours).

Avoid getting dehydrated. In the heat, you can lose up to two litres of water per hour of exercise. Water is the best drink to replace this liquid, but if you've been exercising for a long time, electrolyte replacement is good because it replaces the essential minerals lost in sweat. Most commercial sports drinks are designed to do this and six to eight gulps on each change over should be enough. Don't drink anything that has caffeine in it.

When and how much to drink

Drink about 600ml (1 pint) of water 30 minutes before your match. Then make sure you drink about 250ml (1 cup) of water for every 15-20 minutes of exercise (or at each change over in tennis). Weigh yourself before and after each workout - you shouldn't lose more fluid than 2 per cent of your weight.

Keep drinking after the match and check the colour of your urine. Well-hydrated athletes will pass copious amounts of clear-coloured urine. If your post-match weight is the same as your pre-match weight, that's another sign that you are well-hydrated. You should replace every kilogram lost with one litre of water.


If you're thirsty you are already 2-3 per cent dehydrated. Any dehydration over 2 per cent will mean you perform less well. Good hydration not only decreases the risk of heat illness, it will help you perform better in the heat.

Put ice under your armpits and in the groin area to cool down quickly after a match or practice.

Wet clothes will make it more difficult for you to cool down (they restrict evaporation from the skin), so change your sweat-soaked clothes as often as allowed during the match. Wear clothing made from "wicking" material - it will draw the sweat away from your body and the material will remain dry - thus allowing your body to remain cool during exercise.

Keep out of the sun

Try to keep out of the sun before your match. Remember to use a sunblock! With atmospheric changes, exposure to harmful UV radiation is increasing. Sunblock is essential.

Be really careful if you have already experienced heat illness - if you've had it before, you are likely to have it again. You are also at risk if you have recently been ill, especially if you have a high temperature or have been vomiting or had diarrhoea. Seek medical advice before you go on court.

Wear a hat that keeps the sun directly off your face and directs heat away from your body. A sun visor is best: it keeps the sun away, but does not retain heat. Wear loose, comfortable clothing of a light colour. This helps air to circulate close to the body to allow evaporation. Light colours relfect the sunlight (and reduce the radiation heat load).

Build up your tolerance

Spend some time getting used to exercising in the heat. As your body gets used to working in a hot humid environment, it becomes more efficient at reducing the heat. These changes start a few days after arriving and peak at around 10-14 days. Athletes who arrive earlier for an event will perform better in the heat.

The information provided above is for information purposes only and should not be treated as medical, psychiatric, psychological, health care or health management advice.  If you have any health or related questions or concerns please contact your medical advisor.

Reproduced by kind permission from the WTA Tour.