FACT 1: When the body’s core temperature drops below 30°C (86°F), the body will lose more heat than it can generate by exercising or by external factors, such as sun or fire, which is one of the main causes of hypothermia.
FACT 2: One of the reasons why humans are able to exercise in extremely cold weather is because our bodies can adjust their temperature. In our brain, we have a master regulator that senses changes in the temperature of the blood and signals our bodies to increase heat production to maintain body temperature.
FACT 3: Wind chill plays a significant factor in the extreme cold environment. With a 50mph wind in a minus 20 degree Celsius environment, the temperate you actually experience would be minus 39 degrees.
FACT 4: Temperature during the Yukon Arctic Ultra race ranges from minus 5 to minus 60 and has the potential for heavy snow and serious frost bite. In 2007, competitors were evacuated by air when the temperature hit minus 62 degrees Celsius, making this the coldest race in the world.
Shivering is an involuntary muscle movement with the aim of producing heat. You can temporarily stop shivering, but not for long periods of time. Extreme shivering can produce heat at a rate five times greater than the base metabolic rate.
On average 75 contestants join the Yukon Arctic Ultra race every year from Europe, China, US, Canada and Australia. Only half finish the race.
The Yukon Arctic Ultra 430 miles race runs from Whitehorse to Dawson City. Since 2003, only one person has successfully completed the 430 mile mountain bike race. Alan Sheldon from England holds the race record of 182:50 hours.
Carrying water in this race is very challenging. Some contestants carry water bottles on top of their first layer of clothing and underneath any other layers to keep the water from freezing.
The human body loses more heat when exercising in the extreme cold weather than in other conditions. Increasing muscle activity will lead to an increase in blood flow. This means more blood is circulated away from the core of the body and redirected to the muscles, so heat loss is accelerated.
The competitors in the Yukon Arctic Ultra follow one of the famous routes from the Klondike gold rush. Thousands of people stampeded from around the world to Dawson City at the end of the 19th century searching for their fortunes – and some even did. To date 390 tonnes of gold have come from the Klondike.
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