Wed 30th May, 2012
Exercising in hot weather without taking the necessary precautions can be dangerous, warns Professor John Brewer from the University of Bedfordshire.
As the high temperatures are set to continue, Professor Brewer, Head of Department of Sport and Exercise Science, is advocating a number of measures including drinking plenty of fluids before and after exercise.
“Anyone who exercises in the heat will find that their session is tougher and recovery takes longer, especially if it is an endurance event. Unless we can keep cool during exercise, our core body temperature will quickly rise to dangerous levels, and the human body prevents this by both sweating, and the convection of body heat into the atmosphere.
“But in hot conditions, the ability to sweat effectively is reduced, so we start to rely more heavily on heat convection. To facilitate this, blood is pumped to the skin to lose heat, which puts more strain on the heart, and increases fatigue.”
Professor Brewer recommends that people should drink around 500 ml of fluid an hour before exercise and drink small amounts while exercising to replace the sweat that has been lost. After exercise, keep drinking to regain body weight, and replace fluid that has been lost. Alcohol is not the best way of replacing fluid after exercise.
Other tips include checking urine (it should be a light, straw colour if people are properly hydrated), wearing light clothing while exercising, avoiding working out during the middle of the day when the temperature is at its highest. If you experience nausea and confusion, they are signs of dehydration and should stop exercising.
“These guidelines apply to anyone, whether working out to keep fit in their gym, or competing for medals in the London 2012 Olympics,” said Professor Brewer.
“Our research has clearly shown that both physical and mental performance are impaired in hot conditions. But with a few simple guidelines, and a realisation that physical performances in the heat may not be as good as in the cool, it is possible to exercise safely and enjoyably, and make the most of the fine weather.”