While keeping up with the Kardashians is hard enough, Bruce Jenner thinks keeping up with U.S. gold medal hopeful Ashton Eaton in the decathlon might be even harder.

Before he gained reality television fame as the stepdad of Kim, Khloe and Kourtney Kardashian, Jenner was a 1970s icon when he won the gold medal and set a world record in the decathlon at the 1976 Olympics in Montreal. Even in his prime as an athlete, however, Jenner believes he wasn’t on the level of Eaton, who will compete for decathlon gold in London on Wednesday. Making his first trip to the Olympics since the 1996 Games in Atlanta, Jenner is serving as a special E! News correspondent in London and raved about Eaton on TODAY Tuesday.

“(Eaton is) the greatest decathlete we have ever produced,’’ Jenner said.

Eaton set the decathlon world record with 9,039 points during the U.S. trials last month. American Bryan Clay won the decathlon gold in the 2008 Olympics with a score of 8,791 points, and Jenner’s career best was 8,634 points. Eaton’s performance last month makes the 24-year-old Oregon native the heavy favorite in a sport that encompasses 10 track and field events, from long jump to the 110-meter hurdles. He hasn't even matched Jenner's feat of winning the gold medal yet, but Jenner already believes he is better than any who have come before him.

“I’ll take any athlete you know, any sport, training for 10 years – he cannot do what Ashton Eaton will do in the next couple of days,’’ Jenner said. “The most phenomenal athlete I have ever seen.’’

Slideshow: Olympic hotties: World’s most alluring athletes

Rolf Vennenbernd / EPA

A collection of the winning smiles and champion physiques of Olympic hopefuls from America and other nations.

Launch slideshow

Jenner was considered a phenomenal athlete himself during his heyday. He also is one of the first Olympians to enjoy the marketing bonanza that comes with winning gold, as he famously graced the front of Wheaties boxes. Now he is more well-known as the stepfather of the Kardashian clan, but has no problem with the younger generation recognizing him as an exasperated TV dad instead of a decorated athlete.  

“My generation, our group, they kind of know you from the old days, for all the Wheaties commercials and the games and all those things I did, but certainly the younger group, primarily female, it’s all about being Kim, Kourtney and Khloe’s dad, which is fine with me,’’ Jenner said. “Being a parent is more important than winning gold medals.’’

Read more:

Lolo Jones on virginity talk: 'Maybe I should zip it'

Settling for silver: Why second place is worse than third

Oscar Pistorius: I'll cherish Olympic race 'rest of my life'

Read more coverage from TODAY in London!