Nettlow admits he may be at the “old end” of the racing age spectrum, but the 47-year-old anesthesiologist from Winter Haven, Florida, says he’s not going down without a fight. After discovering the sport in 2003, Don has climbed the corporate ladder of adventure racing to land on Team TravelCountry.com.

Don’s life has been a journey of living big: from barefoot water skiing, to rock climbing, to cross-country hang gliding (logging flights of over 100 miles) to the Ironman, and now PrimalQuest. His goal is to die with no regrets, and his philosophy of life comes from Steve Prefontaine: “To do anything less than your best is to sacrifice the gift.”

“Don’s best strength is that he has no discernable weaknesses,” says teammate Ulf Petri. “He can race a whole day on a few sugar cubes. As he’s shown us again and again, Don’s mental toughness and inability to quit will continue to drive our team to finish what we start to the best of their ability.”

His bicycling friends back home would agree. They’ve given him the nickname “F” – as in “Oh no, F****ing Nettlow is here.” He considers it a great compliment. He also answers to “Psycho Nettlow.” Although, one presumes, not from his patients.