Michael Phelps

Under Armour's latest ad, featuring Michael Phelps, is great. So great that the swimmer himself cried after watching it.

It's easy to see why: The video shows a solitary Phelps grinding, suffering and working hard largely in the shadows, unaccompanied by anyone. The ad's mood is one of obsession, drive, willpower and sacrifice.

Upon release of the commercial, Under Armour also shared Phelps' reaction. But first, you need to see the video for yourself:

As great as the commercial is, Phelps' reaction is even better. Under Armour surprised him with the ad during a visit to UA headquarters. The apparel maker recorded Phelps and his fiancee as they watched and responded:

Phelps will make his final Olympics appearance this summer, four years after insisting to the world that he was going to walk away with no regrets. This video is the first taste of his comeback journey, with more surely to come.

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