There is no coming back now: Michael Phelps

A record-breaking 28 medals in his kitty, the most decorated Olympian Michael Phelps says although Beijing Olympics was the greatest for him the "climb up the mountain" to the Rio Games made it equally special.

Phelps won a staggering eight gold medals in the 2008 Beijing Olympics, winning all the events he participated in. In the 2012 London Games, the ace swimmer went on to win four gold and two silver medals.

The American legend's personal life faced various issues as he went into depression after the 2012 Games, and he later revealed having contemplated suicide.

Phelps announced retirement but two years later returned to the sport in 2014. He went on to win six medals -- five gold and a silver -- in the 2016 Rio Olympics.

"The 2008 Olympics was stats-wise was the best. Hard to say it wasn't the greatest because I won eight medals but coming back to competing in Rio and the journey to it, that climb up the mountain was an amazing process. It was very different from Beijing but I loved it just as much," the 33-year-old Phelps said.

Talking about his journey, Phelps said it was extremely challenging for him to make a comeback but the belief he had on himself made it possible.

"The 2012 Olympics wasn't my best form. It was challenging for me coming off 2008, not really having a goal not knowing where I was going was tough.

"And after 2012, to be able to find the motivation and perform, fighting the odds made my entire journey really special." 

Considered the greatest swimmer of all time, Phelps also revealed what went on in his mind before an event.

"Standing on the block before the race there is absolutely nothing going on in my head. What could be going on their? Nothing, because I can't change how I have prepared for this very moment for that race. All I can do is swim." 

Phelps, who has a unique way of warming up before a race, also said that a lot of swimmers were intimidated by the action.

Just before beginning a race, Phelps famously extends his massive arms and flaps them about his chest and back, slapping himself into the zone.

"I never thought that my arm slap was intimidating, I did it when I was an 11-year-old. Honestly, I didn't think about anyone else when I'm on the block. But a lot of people came up to me and told me they hated that sound." 

Asked if he has any plans of coming back from retirement, the 33-year-old said there were none and he has achieved everything he wanted to.

"In swimming you miss one day it takes two days to get back. So for me when I spent 6 years straight without missing a single day of training I was getting so much more benefit than other athletes who swam six days. I have lost it now there is no coming back now," he said.

"In the swimming world, I have been able to achieve whatever I wanted that's what made 2016 (Rio Olympics) so good," he said at the opening of the first 'Under Armour' store in New Delhi.