Phelps starts life out of the water

London: Like a fish out of water, Michael Phelps started the first day of his new life uncertain where to turn and wondering what to do next.

For the first time in two decades, he didn't need to set his alarm clock to get up before dawn and stuff his swimming trunks and goggles in a bag and head to the pool.

Exhausted from the night before when he finished his incredible career by winning his 18th Olympic gold medal, he had planned to sleep in but his body and mind wouldn't allow it.

He woke at 6 a.m., as always, but with his head still spinning with the magnitude of what he had accomplished and his emotions overflowing as the realisation that it was all over began to sink in.

"I didn't really sleep past the normal time I wake up. I only had three or four hours of sleep last night then I woke up and couldn't fall back to sleep," he told Reuters in an interview on Sunday.

"It's kinda weird, it's very strange, the first day of not having to swim and never having it again."

Phelps had known for a long time that this day was coming after deciding in Beijing four years ago that London would be his last Olympics.

The American knew well in advance what his last race would be and what day it would take place so he started to get himself ready.

He didn't train as hard as he did before Beijing, where he won eight gold medals, but he got himself fit enough and stayed motivated enough to bag another four golds and two silvers and finish his career with a staggering record total of 22 medals.

His final race, Saturday's medley relay, was watched by millions of people around the world and could not have been scripted better.

The crowd inside London's Aquatics Centre let out a mighty roar, instinctively rising to their feet to honour the most decorated Olympian of all time.

He received his gold medal, then a lifetime achievement award from swimming's world governing body and a thousand handshakes and backslaps. There were tears as well, from his family, his coach, even Phelps himself. It was little wonder he hardly slept.

"I'm not sure right now what I feel. It's really confusing," he said.

"I'm all over the place right now. I've got really mixed emotions. I just don't know really how to react yet."

Phelps planned to spend the day with his mother Debbie, but had to fulfill one commitment first, a round of media interviews with his sponsor Visa.

He spent 30 minutes on stage in a packed auditorium answering questions on a wide variety of subjects, ranging from swimming, the food in London and whether he planned to marry soon, then spoke privately to a handful of selected media outlets, including Reuters.

Red-eyed and battling to keep awake, he reflected on his success and talked about his future, saying he wanted to travel more and improve his golf handicap.

The 27-year-old said he wanted to keep in shape after piling on the pounds when he took a short break after Beijing but was not going near a pool again, except to watch the world championships and Olympics.

"The competitive part of my career is over but it doesn't mean my involvement with swimming is over," he said. "I'm still going to be involved, but looking at it from the outside."