One of the most important swimming coaches in U.S. Olympic history never really learned how to swim.
Soichi Sakamoto, who died in 1997 at the age of 91, was a sixth-grade science teacher in Hawaii when he formed the Three-Year Swim Club in 1937 for approximately 100 children of impoverished local sugar plantation workers.
"They had no bathing suits, very little food," Julie Checkoway, author of “The Three-Year Swim Club: The Untold Story of Maui’s Sugar Ditch Kids and Their Quest for Olympic Glory,” told NBC News.
Inspired by the great Hawaiian swimmers of the past like Duke Kahanamoku and previous, smaller-scale success, Sakamoto promised the children that with three years of his rigorous, never-before-seen training, the best of them would represent the United States in the 1940 Olympics.
"He knew nothing about mainstream swimming techniques," Checkoway said. "He used intuition and the scientific method."
For example, Sakamoto invented interval training in swimming. Inspired by Nordic track-and-field trainers, Sakamoto deduced that cardiovascular performance improved when swimmers alternated between going hard and fast, then slow and deliberately.
Without a pool, Sakamoto's charges swam upstream in irrigation ditches, which built up their resistance training.
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"That was an intuitive thing," Checkoway noted. "But it ended up being one of the most scientifically important training methods.”
Sakamoto also emphasized land training more than other swimming coaches. "Their land training included running alongside his car up a hill," Checkoway said laughing.
There was no scientific swimming coaching prior to Sakomoto. ... Because he was a science teacher, he used inductive reasoning. He was the best of what coaches were to become in the 20th century.
The results were instantaneous. Teenagers Halo Hirose and Keo Nakama were both runners-up in their mainland debut, the 1938 Men's Outdoor National Swimming Meet at the University of Louisville. By the next year, they were both national champions. Sakamoto had estimated to the media that five of his proteges — Hirose, Nakama, Jose Balmores, Bill Smith and Fujiko Katsutani — would have qualified for the 1940 Olympics.
But a close-minded swimming community was slow to credit Sakamoto, Checkoway said.
"What was that voodoo he's doing? Witch doctoring?” Checkoway said of the way the rest of the community viewed his techniques. “Very Orientalist thinking. Caucasians tended to discount it until they saw clearly what the results were."
Fellow Hawaiian Kahanamoku helped. "Kahanamoku served as kind of an ambassador for Sakomoto in the U.S.," Checkoway noted. "He introduced Sakomoto to people, gave him a lot of credibility with a lot of people."
It didn't take long for other swimmers to catch on.
Checkoway noted that swimmers would come to Hawaii in the summer to train.
But because of World War II, there were no Olympics in 1940 and 1944. Sakamoto’s pupils were robbed of once-in-a-lifetime opportunities to win a gold medal. Instead, Hirose, Nakama, Balmores and Smith served.
But Sakamoto kept going against the current. Smith, after seeing Sakamoto's early successes, moved to Maui to train exclusively with the non-traditional coach. Smith would win two gold medals at the 1948 London Olympics.
His success now undeniable, Sakamoto was an assistant coach for the U.S. Olympic Swim Team from 1952 to 56. Another of his proteges, Evelyn Kawamoto, took two bronze medals at the 1952 Olympics. “He coached her all the way to the Olympics,” Checkoway said.
"There was no scientific swimming coaching prior to Sakomoto. Everything was intuitive before Sakomoto," Checkoway said. "Because he was a science teacher, he used inductive reasoning. He was the best of what coaches were to become in the 20th century."
She added, "He was doing stuff that nobody did in the mainland. Nobody did in Australia. Nobody did in England. It was revolutionary."
CORRECTION (May 21, 2019, 3:10 p.m. ET): An earlier version of this article incorrectly suggested that author Julie Checkoway had spoken to Soichi Sakamoto She did not; Checkoway was citing interviews Sakamoto gave to other media outlets.