Michael Phelps has once again captured our attention as he adds to his medal collection this week in Rio. He already holds the most medals among Olympians, but there is a pretty emotional man under the skin tight swimmer's cap.

During a screening for his new Under Armour ad earlier this year, the swimmer tears up alongside his girlfriend and mother of his new baby, Boomer. She talks about how the world doesn't know the sacrifice that he makes day in and day out.

There is also to being an Olympic gold medalist that what you see on TV. The video (and soundtrack) are captivating. Watch the UnderArmour ad below: