Complex sentence: He set and still holds the world record in the 50-mile walk (7:23:50), and the Israeli national record in the 50-kilometer walk (4:17:07), and is a former world champion in the 100-kilometer walk.
Split into simpler sentences: He set and still holds the world record in the 50-mile walk (7:23:50), and the Israeli national record in the 50-kilometer walk (4:17:07). He is also a former world champion in the 100-kilometer walk.