Michael Phelps Michael Phelps announced that he'll be entering rehab after his Sept. 30 DUI arrest. Photo: Reuters

Following his Tuesday, Sept. 30 DUI arrest, Olympic Swimmer Michael Phelps has announced he will be entering rehab. The 29-year-old took to Twitter to break the news to his fan base.

In a series of tweets, Phelps explained to his followers the past few days "have been extremely difficult,” and plans to work on himself to “make better decisions in the future.” The posts hit social media Sunday morning:

As we previously reported, Michael Phelps was arrested by the Maryland Transportation Authority Tuesday for driving under the influence in Baltimore. An officer with the Maryland Transportation Authority (MDTA) told CBS WJZ-TV, Baltimore, Phelps had been speeding, traveling 84 mph in a 45 mph zone. The athlete was driving his white 2014 Land Rover at the time of the arrest, and TMZ reported his blood alcohol level was nearly twice the legal limit.

“The officer followed the vehicle onto northbound [Interstate] 95 through the tunnel and initiated an enforcement stop just beyond the tunnel’s toll plaza,” the MDTA said in a statement. “Mr. Phelps was identified as the driver by his driver’s license and appeared to be under the influence. He was unable to perform satisfactorily a series of standard field sobriety tests. Mr. Phelps was cooperative throughout the process.”

Prior to announcing his plans for rehab, Phelps took to the social media site to apologize for his actions. He confirmed he had been charged with a driving under the influence, “excessive speeding and crossing double lane lines.”

This isn’t his first DUI arrest. In 2004 Phelps was arrested at the age of 19, and charged with DUI, violation of license restriction and failure to obey a stop sign. In 2009 the Olympic swimmer also had to apologize after News of the World published a photo of him smoking marijuana from a bong.

“I engaged in behavior which was regrettable and demonstrated bad judgment,” he said in a statement at the time. "I’m 23-years-old and despite the successes I’ve had in the pool, I acted in a youthful and inappropriate way, not in a manner people have come to expect from me. For this, I am sorry. I promise my fans and the public it will not happen again."