Christian Keller. is a former medley

Medley swimming

Medley is a combination of four different swimming styles into one race. This race is either swum by one swimmer as individual medley or by four swimmers as a medley relay...

 and freestyle

Freestyle swimming

Freestyle is an unregulated swimming style used in swimming competitions according to the rules of FINA. The front crawl stroke is almost universally used during a freestyle race, as this style is generally the fastest...

 swimmer from Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, who competed in four consecutive Summer Olympics for his native country, starting in 1992

Swimming at the 1992 Summer Olympics

At the 1992 Summer Olympics in Barcelona, Spain, 31 swimming events were contested. There was a total of 641 participants from 92 countries competing.-Medal table:-Men's events:* Swimmers who participated in the heats only and received medals....

. Four years later the three-time European Junior Champion won the bronze medal with the men's 4×200 m freestyle relay. Keller was named German Swimmer of the Year for two consecutive years: 1994 and 1995.