COLUMBIA, Mo. -- At times overcome by rare displays of emotion, Missouri athletic director Mike Alden said Friday he has reached "the perfect time" to step down after 17 years.

Speaking to students, staff and fans on campus, the 56-year-old Alden said he's thought about resigning for years and made the decision after consulting his family and faith. He issued an open letter through the school Thursday initially announcing his plans, which take effect Aug. 31.

"I've cried a lot over the course of the last five or six days," he said.

Mike Alden grew emotional while discussing his decision to retire after 17 years as Missouri's AD. AP Photo/L.G. Patterson

Citing both Martin Luther King Jr. and Christian pastor Rick Warren, Alden explained that he's always aimed to be "selfless" and felt it was time for someone else to lead, adding that there are no issues with his health.

Chancellor R. Bowen Loftin, whose one-year anniversary with the school comes Sunday, said Alden transformed Missouri athletics and was a factor in his decision to leave as president of Texas A&M for Missouri.

"This is something that came up very recently," Loftin said. "It was a choice that Mike has made. I respect that -- I don't like it -- but I certainly respect it."

Under Alden, Missouri's annual athletics budget has grown from $13.7 million to $85 million and has benefited from $265 million in private donations that have helped fund $233.2 million in facilities upgrades, according to the school.

The department has also prominently been criticized for issues off the field. An independent report said Missouri failed to follow parts of the federal Title IX law that governs sexual harassment on campus when handling the case of former swimmer Sasha Menu Courey's suicide.

The report came in response to an "Outside the Lines" story in January about Menu Courey, who committed suicide after alleging she had been assaulted by players.

The report said administrators on the Columbia campus should have investigated the death after her parents raised questions about the events leading to her suicide.

Missouri changed its Title IX policies after the report.

In 1999, Alden hired Quin Snyder over Bill Self as head basketball coach to replace Norm Stewart. During Snyder's tenure, Missouri incurred NCAA sanctions and an embarrassment when the coach accused Alden of sending team basketball analyst Gary Link to ask Snyder to resign in February 2006. The school's board of curators convened to discuss Alden's future, but it retained him.

"I believe that from each and every one of those challenges, each and every one of those stumbles, and each and every one of those mistakes, that we learned from that and that we grew from that," Alden said. "Isn't that what life is all about? It's not always going to be perfect each and every day."

Alden also hired Gary Pinkel in 2000 as head football coach. Pinkel has since become Missouri's all-time winningest coach with 113 victories and two consecutive East Division championships in the SEC. The program had just six winning seasons from 1980-2000.

"Mike's stuck with me," Pinkel said. "That's one of the things I talked to him about when I accepted the job. I said, `I need somebody that when things get tough, I need somebody to stand next to me and give me an opportunity to build the program.'"

Alden signed a seven-year extension in 2012 that pays a base salary of $301,917. He plans to join Missouri's College of Education after leaving athletics in a role yet to be determined with its positive coaching program.

Information from The Associated Press was used in this report.