This was before Mackey had
won a single Iditarod, let alone four straight; before he used what he calls his marathon style — catnapping as his sled moves and covering 100 - mile chunks at a moderate pace without prolonged rest, instead of sprinting from rest stop to rest stop like most other
racers — to
win an unprecedented double (the Yukon Quest, the world's other 1,000 - mile dogsled race, and just weeks later the Iditarod) not once but twice; before he became so dominant that slower competitors complained they had no chance to finish within five days of him (the requirement for an official place and a commemorative belt buckle); and before a rival pushed for drug testing at the 2010 Iditarod, suspecting that Mackey's secret was his prescription for medical marijuana to alleviate the
side effects of cancer treatment.