The video that brought Olympian Michael Phelps to tears.

Michael Phelps, the most decorated Olympian of all time, was brought to tears after seeing the commercial he helped make to advertise sports wear Under Armour.

The commercial, which is part of the sportswear company’s Rule Yourself campaign, focuses on the behind the scenes work of elite athletes rather than the glory of the win, and shows Phelps’ early morning swims, intense training sessions and the isolation that often accompanies sports people.

The commercial finishes with the line “It’s what you do in the dark that puts you in the light.”

Upon viewing the ad in the Under Armour offices earlier in the week, both Phelps, 31, and his fiancée Nicole teared up. “That commercial shows a lot of amazing things about me that probably the world’s never seen,” Phelps said.

“For me, it’s just incredible. I think it just really shows who I am, and that’s what I wanted,” he continued. “I think the world has seen a part of me throughout my career but I think this is seeing the real me and seeing who I really am, and what goes into everything that I do.”

The Rule Yourself campaign also features footballer Tom Brady, ballerina Misty Copeland and basketballer Stephen Curry.

While Phelps began swimming in primary school, it wasn’t until the 2000 Australian Olympics that the then 15-year-old stepped onto the world stage and began collecting world records.

In the 16 years since, Phelps has won a total of 22 Olympic medals and is the world record holder of the most first-place finishes at any single Olympic Games.

Despite announcing his retirement from swimming after the 2012 London Olympics, Phelps said he will compete at Rio later this year, aiming to take home some more golds before calling it a day once and for all.

On his return, Phelps has said, “I think deep down inside I always wanted to come back. I always wanted to swim and make this my last Olympics. You know, going into London I was just kind of over it. I had no motivation.

“I needed time away from everything, from the sport, from my family, from my friends, from every single part of my life, to be able to just sit down and think about what I wanted to do and where I wanted to go, and who I am, really,” he said.

*All images taken from the Michael Phelps Under Armour commercial.