Huskies

Even untrained huskies are insanely good endurance runners, so you can just imagine how good huskies bred for sled races are.

They'll be charging through arctic weather dragging a huge weight, easily running 160 km per day for multiple days. Emphasis on the unpredictable arctic weather and the weight they need to drag.

The are quite a few instances of huskies covering the 1,100 miles (1,770 km) sled race from Anchorage to Nome (Alaska), in just nine days.

They can even tolerate temperatures of up to -59 degrees Celsius.

This should be obvious, but getting a husky as a pet is definitely a huge commitment due to how much energy they generally have.