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Hot weather hard on athletes

Exercising and activities in the heat can lead to health problems

The first sign of any kind of heat-related health problem is always thirst – by the time we’re thirsty, doctor’s say, we’re already showing signs of dehydration.

With daily high temperatures climbing into the 30s Celsius this summer, Whistler athletes are putting themselves at risk of heat cramps, heat exhaustion and even heat stroke. The effects of these heat problems can run from sore muscles, dizziness, headaches and nausea to full-blown hyperthermia. In rare cases heat-related illnesses can even cause brain damage and death.

While young children and the elderly are particularly susceptible to heat-related illnesses, athletes and people who work outside are also vulnerable.

It is estimated that 20 workers die each year in Canada as a result of the heat. There are no statistics for athletes, although heat illness is listed in the U.S. as the second most common cause of death for athletes under 40, after head injuries.

Health Canada warns that the number of cases of heat illness is likely to increase as average temperatures continue to climb across the country as a result of global warming. People are warned to expect longer hot spells, higher peak temperatures, and more extreme weather events – including hot spells in the spring and fall months.

People in Whistler should be aware of the risks says Jen Leigh, a public health nurse for Vancouver Coastal Health.

"It’s mostly the common sense things that people should be aware of," she said. "For one, you should avoid strenuous activities during the hottest time of the day, which is usually between 10 a.m. and 2 p.m., but you should always use your judgement before and after that. If it feels hot, it’s hot."

You should also wear a hat, and light-coloured, loose-fitting clothing to deflect the sun. Never leave children or pets in parked cars, and be careful when entering a parked vehicle – a few minutes in a hot car can cause problems for drivers.

Everybody should drink about eight to 10 250mL glasses of water every day, says Leigh, and athletes should drink even more.

"Runners should drink an extra two cups of water 10 to 15 minutes before running, as well as another quarter-litre for every two to three kilometres they run. You should always drink before running or hiking and carry a water bottle with you at all times," said Leigh.

Energy drinks are good because they restore electrolytes and sodium to the body, as well as carbohydrates, but they should be mixed 50-50 with water.

The online B.C. Health Guide says athletes need to be aware of the risks. While sweating cools the body, it can also lead to dehydration if you don’t replenish your water supply.

As for water intake, the B.C. Health Guide recommends drinking a cup of fluid every 15 minutes during an event, and to drink sports drinks when possible.

You should also be aware of weight loss, if possible. Athletes should drink half a litre of fluid for every half a kilogram they lose during an activity.

You should also check your urine. It should be a pale yellow, and you should have to go every two to four hours during an activity. If you stop urinating, that’s a sign that you’re not getting enough water.

Prolonged exposure to heat or an activity on a hot day can lead to hyperthermia, or a higher than normal body temperature. The person experiences fever-like conditions because their body can no longer shed the heat through sweating.

If you’re running a high temperature, Leigh suggests placing an ice pack on the back of your neck or under your armpits. If your temperature climbs to 40 degree Celsius, you should call a doctor right away.

Whistler’s Dr. Adam Kendall, an emergency room doctor and sports physician who works with the national freestyle and snowboard team, attended an International Olympic Committee conference in May regarding the games in Athens.

"They are expecting the hottest Olympic Games in 50 years, between 35 and 40 degrees every day with 20 to 60 per cent humidity, depending on the wind," he said. "They’re looking at it as a major issue, to prepare athletes for the heat."

Most of Canada’s Olympic team went to Athens early to spend some time acclimatizing to the temperatures and the humidity. With four to 10 days of training at the higher temperatures, they should be better adapted.

"Most of the athletes are about 75 per cent heat adapted already, just through their training, but they still have to get used to that heat," said Kendall.

Most athletes will try to train with higher body temperatures for 60 to 90 minutes a day. The average body temperature is between 36.5 and 37.5 Celsius, and athletes will try to keep their temperatures around 38.5.

Triathletes on the their way to Penticton for the Ironman Canada competition at the end of the month should also start to train in the heat, he says. Temperatures in the Interior have been in the mid-30s for much of the summer, and have hit 40 degrees from time to time.

"Most of those athletes are out there in the middle of the day training, so they’re getting used to it, but they would do better to spend a few days in Penticton getting used to those conditions as well," said Kendall.

Kendall says he doesn’t see as much heat-related illness in Whistler as he would expect with the summer we’re having, but it does happen. Mostly it’s hikers from out of town who generally are not in shape and not acclimatized to the heat and altitude.

There’s also a chance that people in the early stages of heat exhaustion are going down with mountain biking injuries.

"Some injured riders we’re seeing are definitely fatigued, and heat exhaustion is a possibility in some of those cases," said Kendall. "When you’re tired you definitely don’t think or react as well, and you don’t have as much control over your body either."

Heat cramps are the most common type of heat illness, Kendall says, and can generally be treated by stretching.

Heat exhaustion is slightly more serious. Generally people who collapse at the end of a race are suffering from heat exhaustion, and their body temperatures are one or two degrees above normal. Because most of your blood is in your skin and pooled in your veins, and your heart rate has slowed not as much blood is getting to your brain or organs, which is why people can get dizzy and suffer headaches and stomach aches.

The best way to deal with heat exhaustion is to lie on the ground "which is where your body wants to go anyway," says Kendall, and put your feet up. In some cases people with heat exhaustion can be nauseous, and in rare cases will require an intravenous treatment at the hospital.

Heat stroke is considerably more serious. Heat stroke occurs when your body loses control of its heat regulating mechanisms and your temperature climbs over 40 degrees Celsius. As a result, people feel confused, stumble and lose control of their movements. Vomiting can take place, and the person affected could feel cold and clammy or could be sweating profusely.

If affected, the goal is to bring the body temperature down as soon as possible to avoid brain damage or the possibility of strokes. Placing ice packs in the groin, back of the neck and armpits is most effective, although you can also immerse the affected person completely in cold water.

Although drinking enough fluids can reduce the possibility of contracting a heat illness, Kendall advises people to also be careful not to drink too much. In the past four years there have been eight deaths in North America due to hyponatremia, a condition that occurs when an athlete drinks too much water, blood sodium levels fall to abnormally low levels and the brain starts to swell.

New studies show that it’s better to be a little dehydrated then to carry too much water, says Kendall.

"Most people don’t need to worry about hypnonatremia, but there are cases of people drinking five litres of water before a marathon and having problems. New studies are showing that it might not be that bad to be a little dehydrated," said Kendall. "It varies between activities, but these days the standard is 600 millilitres for every hour of exercise."

Diana Rochon of Dynamic Core Fitness says she has made a conscious effort to work around the heat with her clients, moving training times earlier in the morning when possible, and lowering the intensity of workouts. She has also made sure that they know how to prepare in advance for a session.

"Most of my clients are coming to classes well hydrated, said Rochon. "They’re really good at asking questions about training in the heat, so most of them are wearing hats and loose fitting clothing.

"We can’t do much about the heat so we’re decreasing the intensity of workouts in some cases, spending as much time as we can in the shade, and mixing up our workouts a little by going swimming and doing some cross training.

"For some people it’s been too hot. Everybody is different, so if you feel hot or fatigued, or you’re coming in from work and you’re not feeling great, then we do something else. We all have to listen to our bodies, because problems with the heat can sneak up on you."