BEIJING — He swam so improbably fast, making up so much ground in a foaming, desperate attempt to reach the wall first in the 4x100-meter relay, that Jason Lezak not only won a gold medal for the United States on Monday, he helped to shatter the world record by nearly four seconds.

That race alone would have provided an astonishing day of swimming at the Summer Olympics, but it was the third world record of the morning and seventh in three days of competition. An eighth record was set during preliminary races later Monday, matching the total number broken at the 2004 Athens Games and threatening to eventually surpass the 14 established at the 2000 Sydney Olympics. Not only are world marks tumbling, some are being lowered by staggering margins.

Advances in training techniques, pool design and swimsuit technology have all contributed to the increases in speed for swimmers, who also enjoy financial incentives that allow them to remain in the sport longer than they would have two decades ago, when the Olympics were restricted to amateurs. If Michael Phelps breaks the record of seven swimming gold medals won by Mark Spitz at the 1972 Munich Olympics, he will receive a $1 million bonus from Speedo, the swimsuit manufacturer.

“When you pulverize the world record by more than three seconds, that is remarkable and is only happening very seldom when four superstars are at the peak of their performance,” Orjan Madsen, the German Olympic swimming coach, said of the 4x100 relay record of 3 minutes 8.24 seconds.

At the same time, some swimming officials are questioning whether the multitude of records devalues each one and whether human performance is being unduly aided by technology.

And, as with other Olympic sports, there can never be any certainty that performance-enhancing drugs are not involved. As history has shown with the disgraced track star Marion Jones and revelations about swimmers from the former East Germany, passing a drug test is no guarantee that banned substances are not being used.

“When technology is used in a sport, it is important to be in control of the way it is being developed and where it might lead us,” Claude Fauquet, technical director of the French swimming federation, said in reference to swimsuit technology.

Fauquet has called for more debate about the use of Speedo’s LZR Racer, the latest advance in the full-body suit craze popularized over the last eight years. The Racer has been worn for the setting of about four dozen world records since its introduction in February. The corset-like suit is made by ultrasonic welding instead of stitching, can require a half hour to put on and shoe-horns the body into a more streamlined position, designed to reduce drag in the water.

Critics suspect that the suit aids buoyancy in the water, in violation of performance-enhancing rules set forth by the international swimming federation, known as FINA. Alberto Castagnetti, the Italian national swim coach whose team wears a rival brand, has equated the Racer with “technological doping.” Some believe the suit can boost performance as much as two percent; in swimming, where races are won by hundredths of a second, that can mean the difference between a gold medalist and an also-ran.

“I think sports have to keep up with technology,” said Kirsty Coventry of Zimbabwe, who set a world record Monday while wearing the Racer in a preliminary round of the women’s 100-meter backstroke. “It’s a great suit. For me, putting the suit on, mentally, it’s time to go fast.”

More sophisticated pool design has also helped to dissipate wave action that can slow a swimmer. The Olympic pool in Beijing is three meters deep, compared to two meters for many racing pools. The added depth is designed to lessen water resistance for swimmers by insulating them from turbulence that rebounds off the bottom of a shallower pool.

For major international competitions, like the Olympics, the pool is 10 lanes wide, instead of eight. The two empty outside lanes serve as buffers, keeping the waves from ricocheting, dispersing them instead to a gutter system that is flush with the surface of the water. The plastic buoys that serve as lane dividers, or lane lines, are designed to direct water downward instead of outward. The non-skid starting blocks are meant to facilitate a propulsive takeoff, somewhat similar to track and field, which can shave valuable ticks off the clock.

“If I had to design a pool, this is what it would look like,” said Brendan Hansen of the United States, who finished fourth here in the 100-meter breaststroke after winning three medals at the 2004 Athens Games.

Still, no one can say precisely what is accounting for all of the world records, said Anton Kajlich, whose firm, AntiWave, contributed equipment to the Olympic pool.

“Everybody will claim a different thing,” Kajlich said. “The old timers believe it is really the swimmer and the coach.”

Rebecca Adlington of Great Britain, who won gold in the women’s 400-meter freestyle, said every swimmer expected to lower his or her times during the intensity of an Olympic year. After swimming the second leg of the victorious American 4x100-meter relay team, Garrett Weber-Gale said adrenaline and determination were bigger factors than technology in determining the startling victory.

“It has more to do with the four of us than the pool,” Weber-Gale said. “I think the pool is fantastic. But I think we had an awesome race and we were pushed by the French and the Australians. I think we all just came together. That’s how we were able to go so fast.”

As swimming becomes more popular, it attracts better athletes, who often stay in the sport for more than one Olympics and have access to increasingly sophisticated sports science. Swimmers who once concentrated mostly on endurance now spend up to 50 percent of their training on refining the technical aspects of kicking, pulling, breathing and body position, said Genadijus Sokolovas, director of sports science for USA Swimming. To fully appreciate Phelps’s performance, he would have to be viewed from below rather than above; he is an underwater marvel, streamlined in his turns, ballistic off the wall.

American swimmers here are accompanied by four sports-science experts. Each race is videotaped. Immediately after a race, each swimmer has an ear pricked to test for lactic-acid levels. After a warm-down swim, video analysis is made immediately available to monitor stroke counts, distance per stroke, split times, and the biomechanics of takeoffs and turns.

The nature of swimming also allows athletes to perform in more events than, say, track, providing more opportunities for stars to set world records. Sprinters in swimming tend to train much longer distances than sprinters in track, gaining superior aerobic capacity. They also perform in a horizontal position, which allows easier circulation of oxygen and nutrients through the blood, and they do not pound their muscles, tendons and ligaments, thus gaining quicker recovery. At international competitions, swimmers also generally participate in fewer rounds than track sprinters, which can leave them fresher for event finals.

The suits they wear are likely to become even more sophisticated, perhaps to facilitate muscle contraction and improve kicking power, said Sokolovas, the sports-science director.

“I wish I could compare results from the 70s, 80s and 90s to the current results to know exactly how they are improving because of the suits, technology and training,” he said. “You probably can’t stop technology from coming into any sport. If athletes want to swim faster, technology will always be there. I don’t see it as bad. It’s good for the popularity of swimming. It gets more people interested in sport. And what is the goal of sport? A healthier nation.”