Complex sentence: He only decided to go for the' 36 Olympics a year before, so he did no intensive training in between, but during that time he raced a local Nigerian around the walls of Katsima and lost.
Split into simpler sentences: He only decided to go for the'36 Olympics in' 35, so he did no intensive training in between. During that time, he raced with a local Nigerian around the walls of Katsima and lost.