OMAHA (Nebraska) • Michael Phelps is 31, so, in the world of elite swimming, he certainly can be affected by the physiological.
His can-I-get-you-a-cane walk following an event or two at the US Olympic trials showed that.
But, even after four Olympic appearances, with one more to come, it is clear that the man who has long stood on the blocks and intimidated other swimmers by his mere presence can also be affected by the psychological, too.
"I have a lot of emotion here," the American said.
As he walked on the pool deck on Saturday night at the CenturyLink Centre one final time, the emotion from the crowd poured back.
Four years ago, Phelps said goodbye - only to return for an encore wave.
On Saturday, it turned out to be an emphatic one, with kisses blown after what appeared to be his final race in an American pool, a victory in the 100m butterfly in 51.00sec that gives him another event to swim at next month's Rio de Janeiro Olympics.
Over five Olympic trials dating from when he was 15, Phelps posted 16 victories.
He is assured of a chance at four medals in Rio - in his three individual events, the 100m and 200m fly and the 200 individual medley, as well as in the medley relay, in which he is likely to swim the butterfly leg.
And he may well be a candidate in either of the freestyle relays as well, even leaving open the possibility that he will swim a time trial in the 100m free this morning (Singapore time) just to post a time.
So, take those record 22 Olympic medals and add to them.
"He is who he is," runner-up Tom Shields said. "And you gotta give him that respect."
The respect this time around, though, is deeper because Phelps is different.
He was asked on Saturday night about his physical well-being after he swam two races in one session on Friday - a heat of the 100m fly as well as the final of the 200m IM, which he won.
He talked about how his body reacted but immediately turned, unprompted, to the emotional toll of this meet, his first major competition since the birth of his infant son, Boomer. "With Boomer and with family here and being my last meet on American soil - there was a lot going on this week," he said. "But I'm happy that we did everything we wanted to do."
Like Phelps, Katie Ledecky will also go to Rio having qualified in three events, the 200m, 400m and 800m free.
She hopes to become the first swimmer since 1968 to complete the hat-trick of Olympic gold medals in the distance events.
But Missy Franklin, the 17-year-old darling of American swimming who returned home from the 2012 London Olympics with four golds and was hailed as the sport's brightest young star, is headed to Rio with pared-down expectations and a new appreciation for the pressures that stardom can bring.
She qualified in only two individual events, the 200m freestyle and 200m backstroke, and is assured of another spot on the 4x200m relay team. But she failed to top the podium in any individual event.
WASHINGTON POST, REUTERS