He's tired. His psychic fuel tank is low. He's not sleeping that well. He swims, hurries to awards ceremonies, where he's thinking about the next event, then he rushes to the next event.

Michael Phelps's life these is days is a grind, a pressure cooker, a veritable Olympic rat race. He has so little time for anything. It's eat, sleep, win.

Thursday night it continued. At 8:25 p.m. the champion swimmer from Baltimore County leapt into the main Olympic pool here for the final of the 200-meter individual medley, broke into the lead almost immediately, and won in an Olympic record of 1 minute 57.14 seconds.

It was his fourth gold medal in six days.

But there was no time to celebrate. Thirty minutes later he was on the awards podium, working the kinks from his muscles and thinking about the next race as the national anthem played. Seventeen minutes later, he was back on the starting block for a semifinal of the 100-meter butterfly. It took him 51.61 seconds to set an Olympic record and defeat teammate and arch rival Ian Crocker, who placed second.

Phelps, 19, has six medals total, including two bronze. He has two more days of swimming, and the probability of winning two more medals before the competition ends Saturday night.

Eight medals would tie him with Russian gymnast Alexander Dityatin for the most medals won at an Olympic Games. Dityatin did it in Moscow in 1980, the year the U.S. boycotted the games.

Phelps's initial quest for seven gold medals was derailed by two bronzes he won earlier this week.

But Phelps said after Thursday night's performance that he is not counting medals. "First seven, now it's eight," he joked. "Can't get away from numbers."

His goal is simple: "I'm going to swim as fast as I can swim," he said. "That's all I can really ask; that's all I can really hope for."

Besides, he said: "I'm having so much fun. I'm at the Olympic Games. You can't get much better than this."

Phelps has now raced 3,100 meters in 15 competitions over six days. In practice he has covered about 70,000 meters, and both he and his coach, Bob Bowman, are worried about the strain.

"Once you get to a meet like this, it's so emotionally draining," Phelps said after the last race Thursday night. "Going from one day to the next and having fast swims every single night" is extremely difficult.

"But it's all part of it," he said. "It's all part of the fun. Sometimes my adrenalin is going so high that you can't fall asleep at night. I have to get up the next morning, and I have to deal with that.

"Tonight was the toughest, I think, turnaround time that I've ever had," he said.

He swam the 200 IM, trotted past a throng of waiting reporters to the warmdown pool, where he swam for 10 minutes, went to the awards ceremony, and hurried to the ready room for the 100-meter butterfly.

"He's a little low on gas," Bowman said. "Everybody else has been sitting around waiting to take him on. He's got to get up and slug it out."

Phelps has been on a roller coaster of emotions since the Games began. He won a gold medal in the 400-meter individual medley on Saturday, bringing home the first U.S. gold in the first swimming event of the Games.

But he grabbed only bronze in the 400-meter freestyle relay and 200-meter freestyle Sunday and Monday, losing out on the seven gold medals and the million dollar corporate bonus that went with it.

Tuesday he was back on top, wining gold in the 200-meter butterfly and an exhilarating 800-meter relay. Wednesday he set an Olympic record in the semifinal of the 200-meter IM but swam no final.

But Phelps has prided himself on his ability to take punishment. He is supremely conditioned and recovers from one race to the next faster than almost any other swimmer.

Now the end is in sight. "The countdown has begun," Phelps said.

On Friday morning he likely will swim the butterfly leg in a heat of the 400-meter medley relay, in which a different stroke is swum by each member of the four-person relay team.

Friday night, he has the final of the 100-meter butterfly, again, almost certainly, against Crocker, who twice has beaten Phelps and set a world record in the event at the U.S. Olympic trials last month.

"I can definitely anticipate it's going to be a fast race," Phelps said. "Ian and I have battled it out for the last year. We've been able to race each other a few times, and [Friday's] the biggest one."

The Olympic swimming competition ends Saturday night, with the final of the 400-meter medley relay.

If Phelps should beat Crocker, who so far has had a sub par Olympics, then Phelps would swim the butterfly in the final. He wants it "big time," he said.

"Everybody wants to be on a finals relay," he said.

It's also the last swimming event of the Olympics.

Michael Phelps is off to another medal -- his fourth gold, to go with two bronze -- and an Olympic record in the 200-meter individual medley in 1:57.14. "It's all part of the fun," Phelps said.