What is the "ongoing biological advantage after having trained with the use of PED's"?
Each doping case is different. Those who undeniably with intent and clearly test positive (Ben Johnson, Marion Jones, etc...) Those who have missed multiple out of season testing (whereabouts unknown), which clearly denotes they're avoiding and or hiding something, and those who flat out deny they were cheating, and either unknowingly ingested a banned substance or ingested a banned substance without knowing it was banned (ingredient in a supplement). Each case needs to be punished accordingly with various levels of severity. Case #1 should be a lifetime ban, #2 should be a 4-year ban, and #3 should be a 2–4-year ban depending on various factors (levels found in body, athletes past history, depth of investigation and evidence).