Mezue nkebi ahịrịokwu a: Adamson ruru eru ịgba ọsọ marathon n'Egwuregwu Olimpik nke afọ 1984, bụ́ ebe o ji oge 2:25:02 gbaa ọsọ ma bụrụ onye nke iri ise na abụọ. Ka afọ ahụ na-aga, a na-eme atụmatụ ya ịsọ mpi na 1984 New York City Marathon, mana ọ kwụsịrị tupu mmalite ahụ n'ihi ihu igwe na-ekpo oke ọkụ. N'otu afọ ahụ, o meriri na 1984 Philadelphia Marathon na oge nke 2:16.39, ihe ndekọ mba Jamaica na ihe omume ahụ. Na 1985, Adamson meriri ihe omume ahụ maka afọ nke abụọ n'usoro na oge nke 2:18:27, nkeji 5 na 13 sekọnd n'ihu onye ọ bụla ọzọ. Mgbe agbụrụ ahụ gasịrị, Adamson kwuru na ya nwere olile anya ịgba ọsọ ọsọ ọsọ karịa, mana ifufe mere ka ọ dị nwayọ. Adamson gbara asọmpi na
marathon na 1988 Olympic Games, ebe ọ gbara onye nke iri asatọ na anọ, ma na-agba ọsọ 10,000 mita na 1990 Commonwealth Games, ebe ọ gbara onye nke itoolu.