León faced several difficulties before he could compete in the Games, receiving no support from the Venezuelan Olympic Committee until his arrival in London.

[1] The VOC still did not want to send athletes in 1948, and, according to Julio César León, the only Venezuelan representative at the Games, said they would "make a fool of ourselves".

[1] León tells the anecdote that nobody had thought to bring a Venezuelan flag, as they were unaware of Olympic customs and did not know there would be the pavilion.

He explains that he learnt of it when an Argentine competitor he knew from the South American circuit mentioned it to him in passing.

[2]:26, 317–335 In the sprint event cyclists were drawn in heats of two; the winners would qualify, while the losing competitors contested repechage races before definitive elimination.

[5][2]:322 In the second round, he lost again and thus was eliminated; however, his time and loss to the eventual gold medal winner resulted in León placing sixth.