year s ▁ban ▁from ▁athlet ics , ▁despite ▁UK ▁Athletics ▁feeling ▁that ▁there ▁was ▁reasonable ▁doubt ▁whether ▁the ▁drug ▁had ▁been ▁taken ▁deliber ately , ▁a ▁decision ▁which ▁ignored ▁the ▁usual ▁drug ▁testing ▁principle ▁of ▁" str ict ▁li ability ". ▁ ▁Several ▁theories ▁have ▁been ▁proposed ▁that ▁might ▁explain ▁Christ ie ' s ▁positive ▁test . ▁By ▁way ▁of ▁context , ▁N and rol one ▁is ▁a ▁long - act ing ▁an abol ic ▁ster oid , ▁and ▁is ▁well - known ▁in ▁ath lete ▁circles ▁to ▁be ▁detect able ▁in ▁blood ▁and ▁ur ine ▁screen ings ▁for ▁long ▁periods ; ▁r anging ▁from ▁ 6 ▁to ▁ 1 8 ▁months . ▁S ke pt ics ▁of ▁Christ ie ' s ▁positive , ▁and ▁other ▁N and rol one ▁san ctions ▁in ▁the ▁late ▁ 1 9 9 0 s , ▁have ▁c ited ▁this ▁detection ▁window ▁as ▁a ▁major ▁d eter rent ▁to ▁using ▁the ▁drug ▁at ▁any ▁point ▁during ▁training ▁or ▁competition ▁periods . ▁Ar ound ▁this ▁time ▁pro - h orm ones ▁like ▁ 1 9 - nor andro sten ed ione , ▁And ro sten ed ione , ▁and ▁ 1 - Test oster one , ▁among ▁others , ▁ab ounded ▁in ▁the ▁American ▁supp lement ▁market , ▁and ▁were ▁not ▁yet ▁cod ified ▁as ▁' an abol ic ▁agents ' ▁under ▁the ▁Federal ▁Control led ▁Sub st ances ▁Act . ▁Given ▁that ▁Christ ie ▁tested ▁positive ▁for ▁N and rol one , ▁it ▁is ▁conce iv able