Question: When was John Schaeffer's eight-time medalist athletic trainee born?

Context articles: John Schaeffer (art collector)
John Schaeffer (environmentalist)
Veronica Campbell-Brown
Apolo Ohno
Michael Klueh
Mohamed Abdellah
Krystyna Czajkowska
Carolina Kostner
John Schaeffer
Carl Davis (boxer)

John Schaeffer is a Dutch born Australian art collector and businessman.
 Schaeffer predominantly collects 19th-century British art, specialising in works by the Pre-Raphaelite Brotherhood.
 Schaeffer emigrated to Australia from Holland in the late 1950s, working as a ship's steward.
 In Australia Schaeffer established a security and cleaning company, Tempo Services Ltd., which he later sold.
 In 2004 Schaeffer sold "Rona", the most expensive house in Sydney, which he had acquired in 1989.
John Schaeffer was born November 9, 1949 in Los Angeles, California.
 He is an American environmentalist, author, entrepreneur, and the founder and president of Real Goods, a sustainable lifestyle catalog and Real Goods Solar, a solar electric system installation business in California and Colorado.
 He has been actively involved in promoting and popularizing renewable energy since the mid-1970s.
Veronica Campbell-Brown C.D (born 15 May 1982) is a Jamaican track and field sprinter, who specializes in the 100 and 200 meters.
 A eight-time Olympic medalist, she is the second woman in history to win two consecutive Olympic 200 m events, after Bärbel Wöckel of Germany at the 1976 and 1980 Olympics.
 Campbell-Brown is one of only nine athletes to win world championships at the youth, junior, and senior level of an athletic event.
Apolo Anton Ohno ( ; born May 22, 1982) is a retired American short track speed skating competitor and an eight-time medalist (two gold, two silver, four bronze) in the Winter Olympics.
Michael Klueh (born March 15, 1987) is an American competition swimmer.
 He is an eight-time medalist (four gold, two silver, two bronze) at the World University Games.
 Klueh competed for the University of Texas from 2005 to 2009.
 He is a former Texas 5A state high school record-holder in the 500-yard freestyle.
Mohamed Abdellah (Arabic: محمد عبدالله‎ ‎ ; born March 7, 1968 in Asyut) is an Egyptian sport shooter.
 He is a two-time Olympian, and an eight-time medalist (five golds and three silver) in men's small-bore and air rifle at the African Shooting Championships.
Krystyna Czajkowska-Rawska (born 25 April 1936) is a former female Polish volleyball player, a member of Poland women's national volleyball team in 1955–1968, a bronze medalist of the Olympic Games (Tokyo 1964, Mexico 1968), a bronze medalist of the World Championship 1962 and medalist of the European Championship (silver in 1963 and 1967, bronze in 1958), eight-time Polish Champion, head coach.
Carolina Kostner (] ; born February 8, 1987) is an Italian figure skater.
 She is the 2014 Olympic bronze medalist, the 2012 World champion, a five-time European champion (2007–2008, 2010, 2012–2013), and the 2011 Grand Prix Final champion.
 She is also a medalist at five other World Championships (2005, 2008, 2011, 2013–14), five other European Championships (2006, 2009, 2011, 2014, 2017), and three other Grand Prix Finals (2007, 2008, 2010), the 2003 World Junior bronze medalist, and an eight-time Italian national champion.
 Kostner has won ten medals at the European championships, most recently in 2017, and is the most decorated female singles skater in the history of the European Championships.
John Schaeffer (born March 14, 1951) is an American sports and fitness trainer, author and nutritionist, best known as the athletic trainer of Apolo Ohno.
 He specializes in sports conditioning (physical exercise), nutrition and weight management.
 A five time World Powerlifting and Superheavyweight Kickboxing Champion, Schaeffer owns and operates the Winning Factor Sports Sciences division in Shillington, Pennsylvania, one of the top gymnasiums in the United States, a training and nutrition facility for amateur and professional athletes.
 He frequently travels as a seminar professor to certify personal trainers for the International Sports Sciences Association.
(born November 16, 1973, in Chicago, Illinois) is a retired cruiserweight and heavyweight boxer, and former USBO Cruiserweight champion.
 Davis was trained at one time by Sam Colonna and renowned American sports and fitness trainer John Schaeffer.