Cool runnings: teens and their teams of sled dogs compete for the title of Junior Iditarod champion.
This was Jessica's fourth time to compete in the 225 kilometer (140 mile) race where teen mushers, or dog sledders, go head to head for two days. Their course follows the first section of the famed Iditarod Race route which stretches more than 1,770 km (1,100 mi) from Anchorage to Nome (see Nuts & Bolts, p. 9).
The Junior Iditarod tests the mushers' skills at guiding and caring for their dogs on the trail. But the real stars of the show are the dogs. Given that they'll run thousands of miles in freezing temperatures over the course of a training season, racing sled dogs are considered by some to be the ultra-athletes of the animal world. Find out what makes these dogs so well suited for this sport.
Dogsleds were once a primary means of transportation in Alaska (see "Trail Tale," p. 11). Although most people now get around via snowmobiles and other vehicles, the mushing tradition continues on as Alaska's official state sport.
During an endurance race like the Junior Iditarod, dog sledders spend days braced against strong winds and temperatures that can reach a frigid -40[degrees]C (-40[degrees]F). Being out in the elements can be rough on mushers, but their four-legged teammates love the cold. The canines' thick fur keeps them so well insulated that they can even sleep out in the snow. Dogs also lack sweat glands and have less blood supply to their skin than humans. That helps them trap body heat instead of having it escape through their skin.
If conditions climb much above freezing, the hard-working dogs can actually overheat. One way dogs cool down is by panting. This rapid shallow breathing allows hot air to evaporate. Mushers may also encourage their team to roll around in the snow to cool off. Toward the end of last year's race, warm winter weather took a toll on Jessica's biggest dog, Nanook. "He just wouldn't run anymore," says Jessica. With the finish in sight and competitors closing in, she decided to load Nanook into her sled and jump off the sled's runners to help push from behind.
To train her team of sled dogs for the race, Jessica took them out each day after school on a 56 km (35 mi) trail run. "That level of exercise tends to cause a lot of wear and tear on muscle cells," says Dr. Michael Davis, a veterinarian at Oklahoma State University who studies the physiology of sled-dogs.
Such a strenuous workout would leave human athletes tired, sore, and needing a few days' rest to allow their injured muscles to recover. But sled dogs have the ability to keep going and going. Scientists aren't sure what makes sled dogs better able to weather extreme workouts, but Davis has discovered that somehow the animals' bodies adapt to the stress of racing for days on end. As a result, their muscles don't suffer the continued damage that those of human athletes do.
Davis believes the key to the dogs' high performance comes from their ability to quickly convert the nutrients they consume into fuel instead of tapping into their muscles' glycogen. Human athletes turn to these reserves of stored sugar for energy. The faster a person uses up the supply of glycogen, the faster his or her muscles tire out.
The main factor that limits how far a sled dog can go is food. During race season, the 25 kilogram (55 pound) canines burn up to 12,000 calories a day--the amount of calories in 24 McDonald's Big Macs. It's tough to pack so many calories into a normal-size meal. "To keep from overfilling the dogs, you have to feed them the most calorie-dense nutrient, which is fat," says Davis.
Mushers provide their sled dogs with bowls of special high-fat kibble, pieces of salmon or beef to snack on, and chicken-fat supplements. This keeps portions small yet high in calories.
Junior Iditarod racers are responsible for keeping their dogs fueled and in peak performance condition. When teams reach Yentna Station, where they'll camp for the night, the teens must prepare their dogs' food, melt snow for water, lay straw for the dogs to sleep on, and get ready for the next day's homestretch.
Although strength and speed are important, they're not the only characteristics Junior mushers consider when picking their 10-dog teams. "We also look at each dog's personality and how well they get along together," says Cain.
One of Jessica's favorite parts of racing is strategizing how to build a winning team. "You have dogs on the brain all the time," says Jessica. That devotion helped her take home the 2008 Junior Iditarod trophy as well as a $5,000 college scholarship, which she's using to attend the University of Alaska, Fairbanks.
Jessica is too old to compete in this year's Junior race, which is for kids ages 14 to 17, but Cain will be there. "It's my final year, so we'll see if I can take it," he says. After Jessica's successful win, she now has even bigger aspirations for her team. "The Iditarod is definitely in my future," she says.
Native Alaskans traditionally used dogsleds as a means of getting around the region's snow-covered winter landscape. American settlers adopted the practice when they arrived in Alaska and the Iditarod Trail became the main route traveled by mushers to deliver mail and supplies to towns and outposts across the territory. The trail was made legendary in 1925, when a group of sled dogs set out on a life or death mission. Their task: Deliver medicine to the town of Nome, where a deadly epidemic of the respiratory infection diphtheria had broken out. The first team to arrive was led by a dog named Balto, whose heroic efforts made him an overnight celebrity. Today's Iditarod Trail Sled Dog Race commemorates that historic run.
it's your choice
1. How do sled dogs avoid overheating if temperatures become too warm?
(A) The dogs pant to evaporate hot air from their bodies.
(B) Mushers encourage the dogs to eat mouthfuls of snow.
(C) Sweat glands help keep the clogs cool.
(D) The dogs have a good blood supply to their skin, which helps get rid of excess heat.
2. Glycogen is a type of--that the body stores for energy.
3. The Iditarod Trail Sled Dog Race commemorates a historic run to deliver--
(D) warm clothing
1. a 2. d 3. c
* Do you think you could survive a two-day, 225-kilometer race in freezing weather, driving a dogsled learn?
* What tools and supplies would you need to pack for your clogs and yourself during this journey?
DID YOU KNOW?
* The Alaskan Husky, or Alaskan Malanuite, is the dog most often used in races like the Junior Iditarod. Sled clogs must he trained and conditioned to be capable of withstanding environmental and exercise extremes. They also must show a willingness to be harnessed and a desire to compete.
* All sled clogs that compete in the adult Iditarod are identified by a rice-size microchip and collar tags. The microchips are programmed with an identification number. The microchips are then inserted under the dog's coal and can be read with a special scanner. The identification number can be double-checked against file information on the dog's collar tags.
This ensures that if a tired dog has to be left behind at a checkpoint, the racer will be able to identify the clog when they reunite at the finish line in Anchorage.
* DeeDee Jonrowe, a musher who has raced in the Iditarod for the past 20 years wrote ill her book Iditarod Dreams, "I'm sure the average Iditarod dog gets better care than 99 percent of the dogs in America." Why might Jonrowe have made this statement? How do you think a musher trains and treats his or her canine athletes in order to get them to perform well during such a hard race?
MATH: Calculate the combined amount of calories required by the 10 dogs in each dogsled team during the 2-day Junior Iditarod. Refer to the article to find out how many calories each clog requires per day during the race season (# of calories per dog x 10 dogs x 2 days). If a team in the adult race takes 13 days with 14 clogs, how many more calories do the dogs in the adult race require? (Answer: Junior Iditarod: 240,000 calories, adult Iditarod: 2, 184,000.)
* How do you think mushers communicate with the 10 dogs on their team? Check out the list of mushing terms here: www.iditarod.com/learn/terminology.html.
* To find out more about Alaskan Malamutes, check out the American Kennel Club site: www.akc.org/breeds /alaskan_malamute/index.cfm.
CHECK FOR UNDERSTANDING
DIRECTIONS: Fill in the blanks to complete the sentences below.
1. The course of the Junior Iditarod follows a section of the famed Iditarod Race route, which stretches more than 1,609 kilometers (1,000 miles) from--to Nome, Alaska.
2. Sled dogs are able to trap body heat better than humans because the clogs lack--and they have less--to their skin than humans.
3. Veterinarian Dr. Michael Davis believes that the key to the dogs' high performance comes from their ability to quickly convert the--they consume into fuel instead of tapping into their muscles'
4. The main factor that limits how far a sled clog can go is--.
5. In addition to pulling power and speed, when picking a 10-dog team, mushers must look at each dog's--and determine how well they get along together.
1. Anchorange 2. sweat glands, blood supply 3. nutrients, glycogen 4. food 5. personality