Since the decathlon debuted at the 1912 Olympic Games in Stockholm, the winner of the 10-discipline event at the Olympics has been known as "the world's greatest athlete" after King Gustav V of Sweden decreed the statement about the gold medalist and American legend Jim Thorpe.

Fast forward 104 years, Wisconsin's Zach Ziemek looks to compete for the title of "the world's greatest athlete" this summer by qualifying for the 2016 Olympics Games in Rio de Janeiro. The 2016 NCAA indoor heptathlon champion, Ziemek finished third in the decathlon at last year's USA outdoor championships to qualify for the 2015 IAAF World Championships, where he finished 15th.

So what does it take to be an elite decathlete? The Grind for Greatness takes a look at a typical week of training for Ziemek as he strives to master one of the world's toughest athletic challenges.