It didn't slow him down this time.
Phelps bounced back from a stunning loss with something more familiar -- a world record in the 200-meter butterfly Wednesday. For good measure, he surpassed another of Mark Spitz's accomplishments with the 34th world record of his career, one more than Spitz had during his brilliant run in the pool.
One night after he was soundly beaten by Germany's Paul Biedermann, Phelps sliced the time in what he calls his "bread and butter" to 1 minute, 51.51 seconds, more than a half-second faster than his gold medal-winning time of 1:52.03 at the Beijing Olympics.
With all the hullabaloo over swimsuits, everyone wondered about Phelps' decision to wear one that stretched only from his waist to his ankles, leaving his upper body bare. Was he trying to make a fashion statement?
"No, that didn't even cross my mind," Phelps said. "It was just me being comfortable."
Actually, he had planned to wear a Speedo bodysuit, only to discover during warmups the one he brought to the Foro Italico was too tight in the shoulders. So he went back to the legsuit, which he prefers in the fly anyway.
Phelps went out much faster than he normally does in the fly, and paid for it on the final push to the wall. His arms were burning. His legs, too. But there was no way he was losing again.
He surged to the wall a body length ahead of silver medalist Pawel Korzeniokski, of Poland, with Japan's Takeshi Matsuda settling for bronze. Phelps whipped around quickly to see his time and held up his right index finger when the "WR" was posted.
"I wanted to step on it in the first 100 to get out there in the clean water, and that's pretty much what happened," Phelps said. "It was a lot more pain last night than tonight."
On Tuesday, he was blown out of the water by Germany's Paul Biedermann, who routed Phelps in the 200 freestyle and also snatched away his world record.
Most of the talk afterward was about what they were wearing -- and there wasn't a red carpet in sight. Biedermann was in a polyurethane Arena X-Glide suit, which everyone concedes produces much faster times than Phelps' year-old Speedo LZR Racer.