Like the world's top athletes, sled dogs undergo arduous training to develop a will of steel and a strong physique. Sultana is such an excellent sled dog, whose genes endow her with a love for running, a passion for work and a super adaptability to the wild environment. So you won't see them on the training ground. The sled dogs are trained on the ground in the freezing and snowy environment and grow in battle. In Alaska's Denali National Park, they are gearing up for the next working season.

Eight-year-old Sultana is a standout among sled dogs. (Photo taken in Denali National Park, Alaska)

A wave of jobs is challenging sled dogs all over the world, and a large number of supplies for work and travel need the help of sled dogs to carry. International events such as the Iditarod dog sled race in Alaska and the Yukon sledding sport also attract about 1,300 sled dogs and thousands of people from all over the world to the snow-capped city of Alaska.

Contrary to popular belief, Siberian Husky sled dogs and Alaskan Malamutes are not workhorses. The True Seed is an unofficial breed, a sled dog bred by humans specifically for racing and hauling. Don't be fooled by their aggressive little ruffian faces, these hard-working and vigorous sled dogs can pull hundreds of kilograms of cargo across snow-covered areas at a time like a machine that never needs a break. It is a good working partner of human beings.

As a sled dog, appearance is obviously not the most important thing, and pedigree is not judged (please note: it is not a beauty contest). The most important thing is the performance of the work, no matter whether the cat is black or white, as long as it can catch mice, it is a good cat. Howard Thompson, who now specializes in sled dogs in Wisconsin, said: There has to be a belief, the spirit of being home. It feels like the scenery is always elsewhere. Only then can you keep running.

Then, the sled must have a good appetite, and must not be picky eaters, no matter when and where. Long-distance treks in the cold environment will consume a huge amount of physical energy, sled dogs like Sultana, often receive a need to travel up to 483 kilometer or even farther daunting task. Completing such a task can range from a few days to a few weeks. It is not allowed to be picky about food in the days of wind and sleep.

“A sled dog has to have a strong physique, especially claws of steel that are indestructible,” adds Charlotte Mooney, who breeds sled dogs in Montana. When competing, we can use professional tools (similar to human boots) to protect the sled dog's paws. But this will greatly slow down the sled dog's running speed. The same does not apply to such short-distance projects (less than 48 kilometers). You know, they run at a speed like the wind and lightning.