At just 14 years old, he participated at the 1979 Pan American Games, in San Juan, where he finished seventh in the 400-metre individual medley, and eighth in the 200-metre individual medley. Prado participated in the 1980 Summer Olympics, in Moscow. He swam the 400-metre individual medley and the 100-metre backstroke, not reaching the final. On 8 August 1982, at the 1982 World Aquatics Championships in Guayaquil, Prado won a gold medal in the 400-metre individual medley, with a time of 4:19.78, establishing a new world record that stood until 23 May 1984. Prado was also in four other finals: placing fourth in the 200-metre butterfly, and eighth in the 200-metre individual medley, the 200-metre backstroke, and the 4×100-metre medley. Prado had chances to earn a good result also in the 200-metre individual medley, but the conditions were adverse in Ecuador. "The hotel we stayed at was not well attended. It was directly across the Guayaquil bus station. I managed to reach the final of the 200-metre individual medley, but I was weak because food there was terrible, and finished the race in eighth place." Prado landed at home with gold on his neck but a big mycosis in his belly. Djan Madruga had worse luck: he contracted typhoid fever. At the 1983 Summer Universiade, in Edmonton, Prado won two bronze medals: in the 200-metre and 400-metre individual medley races. He also finished fourth in the 200-metre backstroke, and sixth in the 200-metre butterfly. Prado competed at the 1983 Pan American Games, in Caracas, where he won two gold medals in the 200-metre and 400-metre individual medley. He also won two silver medals: in the 200-metre backstroke, and in the 200-metre butterfly. Prado won the silver medal in the men's 400-metre individual medley at the 1984 Summer Olympics in Los Angeles, California. He also finished fourth in the 200-metre backstroke, 12th in the 4×100-metre medley, and 17th in the 200-metre individual medley and the 200-metre butterfly. Prado participated in the 1985 Pan Pacific Swimming Championships, the first year of the competition, where he won the gold medal in the 400-metre individual medley, and the bronze medal in the 200-metre butterfly. He also finished fourth in the 200-metre backstroke. At the 1985 Summer Universiade, in Kobe, Prado won the gold medal in the 400-metre individual medley and the bronze medal in the 200-metre individual medley. He also finished fourth in the 200-metre backstroke and in the 200-metre butterfly. At the 1986 World Aquatics Championships in Madrid, Prado competed in the 200-metre individual medley final, finishing seventh. Although feeling the exhaustion of years of competition, Prado still swam at the 1987 Pan American Games, in Indianapolis, where he won a silver medal in the 200-metre backstroke, and two bronze medals in the 200-metre individual medley and the 4×100-metre medley. Prado began to decline after losing the gold in Los Angeles 1984 to Alex Baumann. In 1987, Prado felt tired with his star status. During that year, he still swam well, earning medals in the Pan American Games, and spoke to journalists about training for the 1988 Olympics in Seoul. In early 1988, Prado's positive diagnosis for hepatitis marked the inevitable. Prado said goodbye to competitive swimming after racing for 23 years.
Marks and records
In addition to beating the world record of the 400-metre individual medley, Prado held five South American individual records at the same time, at the 1983 Pan American Games in Caracas. At this competition, he broke Djan Madruga South American record in the 200-metre backstroke, with a time of 2:02.85. This record would not be broken until the 1988 Summer Olympics in Seoul by Rogério Romero, with a time of 2:02.26 in the heats. In Caracas, he also broke the South American record for the 200-metre butterfly, with a time of 1:59.00. This record was not beaten until 2003, 20 years later, by Kaio Almeida. Prado broke the South American record in the 400-metre individual medley at the 1984 Summer Olympics, with a time of 4:18.45. This record was only beaten 20 years later, in 2004 by Thiago Pereira. In the 200-metre individual medley, Prado broke the South American record in Clovis, California, in 1983, with a time of 2:04.10. This record lasted 20 years and was beaten in 2003 by Diogo Yabe.
