you need to read the book - I read an excerpt and it was a case of cutting-edge steriods administered in regimines designed to avoid detection by the standard tests. In fact, one or two of these designer steriods were unknown to even the FDA until Victor Conti & his BALCO cohorts were busted a couple of years ago.
Sheffield has always been a gbig guy, unlike Bonds. And he has never failed a drug test. He says he used some cream (that Bonds sent him) for a knee problem, for a couple of weeks until he found out what it was and then he stopped.
Given the consistency of Sheffield's performance, I can believe that. Giambi is another matter, as it appears that he admitted to using, and Bonds certainly bulked up a lot in the later years of his career.
However, the San Francisco Chronicle is an unreliable source on anything, and anything that two Chronicle reporters tell me, given the paper's apparent view that socialism is too right wing -- which is even more pervasive in its reporting than in its editorial pages -- I would tend to take with a full box of salt. (Like most liberal news outlets, they don't even try to get the story right, just politically correct. The story of the rescue of the pinko peacenik hostages is one of the best examples of how liberals would rather distort for a political point than actually make an effort to get the story right.)
And the media is well-known to have a strong and long-standing animus towards Bonds, at least in part because he has never catered to them and that hurts their egos.
Furthermore, these authors know that trashing big names makes them big names and makes them more money. For people who hate capitalism (requried to work at the Chronicle), they sure do practice it.
That doesn't mean that Barry didn't juice up -- just that these guys have an agenda, so I'll need more than this before I'm sold on the idea that it's "proven."