Michael Phelps

Swimmer Michael Phelps poses for a portrait during the 2012 Team USA Media Summit on May 13, 2012 in Dallas, Texas. (Ronald Martinez, Getty Images / May 13, 2012)

"Ryan doesn't think at all," he said, "and Michael overthinks."

Lochte is coming off of a series of wins in international competitions over Phelps, who admittedly lost his focus and drive in the wake of the Beijing Games. But Phelps bested him at the trials, beating him in all but one final, making their two rematches in London, in the 400- and 200-IMs, can't-miss events.

But if Lochte poses a threat to Phelps' supremacy, he seems to also have energized him. There is a sense that Phelps, whether by personality or his status as head and shoulders above the rest of the pack, might feel the loneliness of being on top and relishes some company, even in the form of a rival, up there.

Neither is much for trash-talking. The closest Lochte gets is saying London is "his" time, Phelps won't even go that far — and, in fact, hardly needs to.

"Michael doesn't need to say anything," Krayzelberg said. "They know they're racing the best swimmer in the world."

Phelps will indicate, though, that he thinks Lochte made a strategic misstep in the trials by swimming three races in a single day, the dreaded triple that Phelps himself will avoid in London. Although he emerged from trials on track to swim the same eight events in London that he swept in Beijing, he dropped one race, the 200-free, in favor of more rest time between the grueling 400 IM on the first day of competition and the high-profile 4x100-meter free relay on the second.

While a concession to age and, in his post-Beijing funk, a later start to preparing for London, the decision lifts the onus of Phelps having to compete against himself, or rather, his greatest-hits album of 2008. Rather than having to match his younger self, whatever he accomplishes in London has a better chance of being judged on its own.

But what Phelps wants to do in London remains something of a mystery. If the 2004 and 2008 Games were about chasing, and ultimately surpassing, Mark Spitz' record of seven gold medals in a single Olympics, his current goals are less easily quantified, at least for public consumption.

He will allow that he is motivated by firsts. He could, for example, become the first male swimmer to earn gold in the same event in three Olympics by winning his first event, the 400 IM. And given that he'll have two more chances to do that, he conceivably could three-peat the three-peat.

And by winning just three more medals, of any color, he could supplant Russian gymnast Larisa Latynina's record of 18 to become the most decorated Olympian ever.

Given his performances this past season, both goals seem in reach, although the ever-cautious Phelps would say that in any competition, it's a matter of who shows up and delivers.

By now, he has sweated all of the details, studying videos of his races to find ways of shaving a fraction of a second off a turn, or buying one with a faster start. He has swum with his goggles blackened out, to make sure he can swim through darkness — which of course is what happened in the 200-meter butterfly in Beijing, when water flooded in and blinded him during the final laps.

Even when he's not swimming, he's working, or at least, his body is working: he wears a compression suit to help his body recover. At home in Baltimore, he has slept in a hyperbaric chamber to make his lungs work as hard as if he were at 10,000 feet in altitude.

Still, the Phelps of today is less the single-minded Phelps of the past; they are in fact "like two different people," his coach Bowman said.

"One was like a machine — well, half-man, half-machine," Bowman said earlier this year, "and one is like a man."

The machine didn't take a single day off from the pool between the ages of 13 and 18, a glutton for the kind of punishing workouts that produced his record gold medal haul and shattered world records right and left. The man is the one who after 2008 blew off practices for the golf course or the poker table and left him newly vulnerable to the Lochtes of the world.

The hard-driving Bowman jokes that he liked the machine better. But even he views these final Games as not so much for the record books — Phelps has already filled more than his share of pages — but for the swimmer himself.

"He has worked so hard," Bowman says of the years of training that have taken Phelps to this final Olympics. "I'd like him to just enjoy it more."