Iowa coach Kirk Ferentz admitted mistakes Wednesday in his handling of the hospitalization of 13 players with a rare muscle disorder, but he said their workouts were safe and he remains puzzled about the cause.

Ferentz said he could have delayed an out-of-state recruiting trip and visited the players in the hospital a day earlier last week. He said he also erred in thinking his presence at the hospital after he returned would be calming to parents, some of whom were upset.

Ferentz addressed the news media for the first time one week after the university announced 13 players were affected by rhabdomyolysis, which causes muscle fibers to be released into the bloodstream and can cause kidney damage. The players spent several days getting treatment and were released between Friday and Sunday.

Physical exertion is one of several causes of the ailment, and the players were among about 80 who had participated in intense workouts that started Jan. 20 after they returned from winter break. One of the workouts involved performing 100 squats in a certain amount of time.

Ferentz said his teams had gone through similar or even more challenging workouts in 2000, 2004 and 2007 and were not affected. He said the workouts were designed to be rigorous and safe, not punitive. His son, the team's starting center James Ferentz, went through the program and was "stiff and sore" but recovered.

"I can't pinpoint a cause for this. To me, it's very random. We went three times without incident, and now this," the coach said.

A university investigation into what caused the ailment is underway, and Ferentz said he looked forward to the findings. That investigation is expected to be wrapped up in 90 days and meant to ensure a similar episode doesn't happen again. Ferentz said the workouts in question would not be repeated.

In other college football news: Former Southern California backup quarterback Mitch Mustain was arrested on suspicion of selling prescription drugs in the San Fernando Valley. Mustain completed his senior year for the Trojans in 2010 and is preparing for the NFL draft.


Tennis: Defending champion Feliciano Lopez joined the parade of seeded players exiting the SA Tennis Open in Johannesburg, South Africa, becoming the fourth to fall when he lost 6-7 (5), 6-2, 7-6 (8) to Frank Dancevic in the first round.

WNBA: The Los Angeles Sparks signed forward Ebony Hoffman to a free-agent contract, and guards Ticha Penicheiro and Noelle Quinn have re-signed with the team. ... The Indiana Fever signed veteran center Tangela Smith to a multiyear deal.

Baseball: Lou Piniella agreed to a one-year contract with the Giants to work as a special assistant for the World Series champions. ... Roger Clemens told a federal judge that he waives any conflict of interest that may arise from his lead criminal defense attorney briefly representing his former-teammate-turned-accuser Andy Pettitte.

In the courts: A trio of Nevada Supreme Court justices denied O.J. Simpson's request to revive the appeal of his conviction in a Las Vegas casino-hotel room heist.


Bryant defends diving crown

The Gophers' Kelci Bryant successfully defended her 1-meter title and claimed her eighth career national title at the 2011 USA Diving Winter National Championships in Iowa City. Bryant, a 2008 Olympian who also won the 1-meter at the 2010 winter nationals, scored 283.9 points.

Anderson wins Beargrease

Ryan Anderson of the northern Minnesota town of Ray has won the John Beargrease Sled Dog Marathon in a neck-and-neck finish.

Anderson and his 11 dogs crossed the finish line in Duluth on Wednesday morning just 20 seconds ahead of defending champ Nathan Schroeder, of Chisholm, and his 10 dogs.

The teams set off Sunday afternoon for the nearly 400-mile trip from Duluth up the North Shore of Lake Superior, up the Gunflint Trail and back to Duluth. Anderson crossed the finish line shortly before 9:30 a.m. Wednesday with a little under 40 hours of total time on the trail.