Career
Klein was so exhausted from the bout – the longest wrestling match ever recorded – that he was unable to wrestle for the gold the next day, leaving Swedish wrestler Claes Johansson with the gold medal. Klein was born to a farmer and started training in wrestling only in his twenties. Seeking additional incomes, he became a night-shift guardian in a wrestling club and in this way was introduced to the sport.
Besides the 1912 Olympics, he also competed at the 1913 World Championships, but withdrew due to a hand injury.
During World War I he served in the Russian army and later took part in the Estonian War of Independence. In 1919 he became a wrestling coach and prepared Estonian wrestlers for the 1920 Olympics.
At those Games he was also offered a place as a competitor, but refused in favor of his younger teammates. Klein continued coaching and competing in wrestling in Estonia until 1937.
He died as a consequence of a hernia, which he developed when moving logs.
Since 1962 an international Martin Klein Memorial in Greco-Roman wrestling is held in Viljandi, Estonia.