Boy, did it hurt.
"I'm in a world of pain right now," Phelps said Thursday during a teleconference to mark yet another award: his selection by the U.S. Olympic Committee as its sportsman of the year for 2008. "It's all over my body. I'm almost in a state of shock. Literally every part of my body is hurting."
Phelps resumed formal training Tuesday with longtime coach Bob Bowman. The swimmer spent a little over an hour in the weight room, a session that included sit-ups and other abdominal exercises. He also worked about an hour in the pool, trying to recapture the form that carried him to eight gold medals in China.
It's not going to be easy coming back from the longest break of his career, a time spent having fun, moving back to his hometown of Baltimore and cashing in on his iconic performance with everything from a new book to hosting the season premiere of "Saturday Night Live."
Still, he's eager to get started on what will be the farewell run of a brilliant career, building up to his final performance at the 2012 London Games.
"I feel like I have some normality back to my life," Phelps said. "I can get to sleep earlier. I have no problem falling asleep now. I was completely worn out my first day back. After two hours or so of working out, I was absolutely dead. I had no problems falling asleep at 10 or 10:30 that night. It feels good to add some scheduling back to my life. The more I start getting back into it, the better I'm going to feel."
Phelps hasn't decided which events he'll swim as part of his latest program, but he's definitely planning to lighten the load after swimming eight events at each of the last two Olympics. He won six gold and two bronze medals at the 2004 Athens Games, then won all eight events in Beijing to break one of sport's most treasured records -- Mark Spitz's seven golds at Munich in 1972.
"I'll never swim eight events at a major competition again," Phelps vowed. "I'm almost positive that my last eight-event meet was Beijing."
For his first competition since the Olympics, Phelps is pointing toward a Grand Prix meet that begins March 4 in Austin, Texas. He plans to compete at this summer's world championships in Rome.
Phelps put on 15 pounds during his post-Olympic whirlwind, and he sure felt that extra weight on Tuesday.
"I knew it wasn't going to be easy," he said. "It's time to stop fooling around and get back into shape."
For advice, he called up another Olympian, Erik Vendt, who thought he was done with swimming after Athens, only to return to sport following a nearly two-year layoff. He made the U.S. team for Beijing.
"I talked to Vendt (on Wednesday) and I was like, 'Dude, how did you do that?"' Phelps said. "He told me, 'Well, I knew it was going to hurt, and I just didn't care. You've got to push through it.' That's the kind of mentality you have to have. This is a kind of pain that I've never experienced in the sport. I kind of expected it. The biggest thing is you have to push through it."
While eight golds is no longer a goal, the 23-year-old swimmer made it clear he's still motivated to win races and conquer new challenges. If not, he would have retired after Beijing.
"Obviously, this is the last four years on my career," Phelps said. "I don't want to come back and swim these four years and not be satisfied with how it went. I still have my goals and I want to make sure I reach my goals and accomplish my goals. I don't think it's going to be as intense as the last four years, but it's still going to be intense. The goals I set will not be a cakewalk to achieve. They're going to be high goals."
While not specifics about what events he might attempt, Phelps will surely drop his toughest race -- the 400-meter individual medley -- and focus more on freestyle and backstroke.
"I'd really like to see him do some backstroke," Bowman said last month. "He's really good at it, but he's never gotten to swim it at a big event."
Phelps returned to training just two days after attending the AFC championship game in Pittsburgh with his hometown Ravens.
The Steelers won a hard-hitting game 23-14, ending Baltimore's season just one victory short of the Super Bowl. Still, Phelps plans to follow through on his plans to attend the Feb. 1 game in Tampa, Fla., a trip tied in with appearances on behalf of one of his myriad sponsors.
"We had a great year," Phelps said of his favorite team. "The guys played well. A couple of them are pretty good friends of mine. We were all pretty sad, but after having a 3-13 year last year, that was a pretty solid year with a rookie quarterback (Joe Flacco). We're on the right track."
Phelps believes he's on the right track, as well. As bad as he's hurting right now, he looks forward to enjoying the sport more than ever.
"I'll have more time to take in more experiences, possibly being in the stands cheering," he said. "I've not had that experience since 2001 at my first world championships. Really, just being part of the team more. When you're swimming so many events, all you do is eat, sleep, swim, eat, sleep, swim. You never get to be in the stands. You're always warming up, warming down, going back and forth to the pool, eating at the village and going to sleep.
"This is something I'm looking forward to. It's something that should be fun."