Complex sentence: He was a dedicated supporter of sports: and he is a Master in Sambo, he gained a champion of the Russian Federation of Sambo in 2000 and he became the world champion in Sambo among veterans in the weight category of over 100 kilograms.
Split into simpler sentences: He was a dedicated supporter of sports and he is a Master in Sambo. He gained a champion of the Russian Federation of Sambo in 2000 and he became the world champion in Sambo among veterans in the weight category of over 100 kilograms.