Since Michael Phelps won his 11th gold medal in the 4x200 freestyle relay on Wednesday morning, he's been called the greatest Olympian of all time.
By medal count, yes. Phelps has been spectacular, out of this world, a show unto himself. And he has three races still to go.
As U.S. Olympic Committee CEO Jim Scherr told Alan Abrahamson of NBCOlympics.com after Phelps swam the lead-off leg in the 4x200m relay, "I hope people realize just how difficult what he's doing is. We will never see anything like it again."
Latynina competed for the Soviet Union in the 1956, 1960, and 1964 Olympics, medaling 18 times.
Nurmi was equally out of this world. The Finnish runner won the 10,000 meters, cross-country race, and team cross-country event at the 1920 Olympics. In 1924, he won five golds (cross-country and team cross-country again, a 3000 meter team race, the 1500 and 5000). In 1928, he won his ninth gold in the 10,000. He also earned three silvers for his collection.
It's difficult to compare gymnastics to sports with finish lines. So I decided to look at Phelps' achievement (to date) to that of Nurmi who, like Phelps, raced day after day, breaking Olympic records (although the team cross-country races were not separate events; they took the times from the three Finnish runners in the individual cross-country race and added them). Nurmi might have won 10 golds had his coaches allowed him to race the 10,000 in 1924 (they thought he was entered in too many events).
The best way to fairly compare them, I decided, was to quantify their gold-medal races. For how many hours and minutes was each man engaged in a competition where he won gold? Using David Wallechinsky's The Complete Book of the Olympics, I took Nurmi's and Phelps' times, and - remembering my sixth grade math - added them.
Over three Olympics, Nurmi ran for almost 1.5 hours in the races that he won.
In the 2004 Olympics, Phelps swam for just over 25 minutes to earn gold (I included heats and semis by taking his time in the finals and rounding them up). In Phelps' five gold medal swims to date in the 2008 Olympics, he has been in the pool for 21:37.63.
In earning 11 golds, Phelps has been in the water for less than an hour. This, of course, doesn't take into account the hours (days, months, years) in the pool training for these few minutes.
Which made me think of Bjorn Daehlie, the Norwegian cross-country skier who collected 12 Olympic medals - 8 gold, 4 silver - from 1992 through the 1998 Olympics. To earn his 8 golds, Daehlie poled, kicked, and glided a total of 180 kilometers. It took him in a shade under 8 hours.
This led to the question that's come up in the months since I've been covering the Olympics: What is the hardest sport?
Weightlifting certainly looks hard, and the wrestlers I've interviewed insist that their sport is the most difficult. Same with boxers. And triathlon, who could argue? As an endurance athlete, I've competed over the years in rowing, cycling, and cross-country skiing - all of which my coaches insisted were the hardest sports (and after workouts where I saw spots and tasted blood, I believed them).
What do you think is the hardest Olympic sport? And who do you think is the greatest Olympian ever?
Peggy Shinn is a freelance contributor for teamusa.org. This feature was not subject to the approval of the United States Olympic Committee or any National Governing Bodies.