Nepomuceno also served as a sailor in the United States Navy and died in the line of duty.

Along with fellow Filipino Fortunato Catalon, he was considered a world-class sprinter in the 1920s, competing frequently in the Far East.

[4] He was the sole participant representing the Philippines, making him the first Filipino to compete in the Olympics.

[1][10] In a magazine interview, he was quoted "Sana yung mga susunod sa akin ay hindi maranasan ang naranasan ko (I hope those who come after me will not experience what I experienced)”.

In 1925, he nearly shattered the world record for the 100 meters, finishing just two-tenths of a second behind the then-record holder, Charley Paddock.