Extreme Humans

Dean Karnazes – The Ultramarathon Man

Last Updated on May 26, 2020 by Darshan Modi

Dean Karnazes
Dean Karnazes


Dean Karnazes (born Constantine Karnazes) is super-endurant and can run for days without his muscles getting tired.


Dean Karnazes was born on August 23, 1962 in Inglewood, Los Angeles Country, California, USA.

Early Life

He fell in love with running at an early age: as a child, Dean Karnazes took up running for fun. During kindergarten, he would run from school to his home.
In his third grade, he organized and participated in short running events with other children.
At the age of 11, Dean Karnazes had hiked across the Grand Canyon and climbed Mount Whitney.
He had been expelled from school twice because of attending school drunk, but the love of running overcame his love of alcohol.

About Dean Karnazes

He ran a marathon to the South Pole in ?13 °F temperatures without snowshoes.
Amongst multiple other rewards, he has won the Badwater Ultramarathon in 2004, which took place across Death Valley in 120 °F temperatures
One of Dean’s most notable achievements is when he had ran 350 miles in 80 hours and 44 minutes without sleep.
Furthermore, he is famous for running a marathon in each of the 50 American states in just 50 days.
He has also participated in a swimming event that included swimming across the San Francisco bay.
His athletic achievements led to him writing multiple books, including “Ultramarathon Man: Confessions of an All-Night Runner”, with which he became a bestselling author.

Genetic Or Learned

The body’s scientific limit is the lactate threshold. Exercising beyond it causes muscle unpleasanty, fatigue and rapid heart pounding.
Dean’s body limit defies every other man’s physiological performances.
He realized that he’s biologically different during a physical testing center where they performed a lactate threshold test.
Through a chain of bodily chemical reactions, lactate is cleared from the blood and later transferred into energy.
Some sources say that Dean’s lactate clearance abilities wouldn’t have been the way they are now if he hadn’t ran as a child.
Dean believes that his lactate clearance abilities are due to his low body fat, highly alkaline diet and low exposure to environmental toxins.
From this information we can conclude that the ability is both genetic and learned.

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Names Known By

  • Ultramarathon Man


Featured In

  • The Late Show with David Letterman
  • Late Night with Conan O’Brien
  • BBC
  • CBS News
  • CNN
  • ESPN
  • The Howard Stern Show
  • TIME Magazine: “Top 100 Most Influential People in the World”
  • Newsweek
  • People
  • GQ
  • The New York Times
  • The Washington Post
  • Men’s Journal
  • Forbes
  • The Chicago Tribune
  • The Los Angeles Times
  • “Ultra Marathon Man” episode of Stan Lee’s Superhumans documentary television series
  • Men’s Journal, Adventure Hall of Fame, 2007

Books Published

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