This is a copy & paste of a post that I flagged on a Mariners site that I frequent. It's the best thing I've read about what steroids do (and don't do) to the body and how they would help a baseball player. Major kudos for the guy that posts under the name "Matt Staples" on Sportspot.
Myth: All steroids do is make you more "muscular" and/or "stronger" in the blanket sense of the term.
Educated Opinion: Steroid use not only enables hypertrophy (the growth of muscle fibers) -- and perhaps hyperplasia (the development of new muscle fibers) -- in fast-twitch muscle fibers (i.e., type IIB), but it would also have benefits on the neuromuscular side of things as well. Additionally, as a third, related benefit, they allow for quicker recovery from bouts of exercise and injuries (two separate concepts, each important).
All three of these could have some effects that would benefit a hitter. Hypertrophy of fast-twitch muscle fibers would allow for more forceful (and hence quicker) swings. This lets someone wait longer before swinging. This ability to wait on the ball happens to be the one of the abilities that Bonds has greatly improved on in the last few years.
The second point, relating to steroids' ability to improve the neuromuscular activity of an athlete, is more controversial, but it shouldn't be ignored. I can't go on Medline and look this up -- well, I could, but I'm not going to -- androgens increase what can only colloquially be described as the "mind muscle connection." To put it in layman's terms, steroids would not only let a guy be able to get the bat through the zone more quickly faster due to more muscle, but also due to what is best described as a better mind-muscle connection. This is a different concept than hand-eye coordination, and has more to do with the ability of a person to contract skeletal muscles in response to stimuli. They can make a person "stronger" without necessarily making that person bigger. This, I would assume, is why so many pitchers would be rumored to have used them in the past few seasons. Sufficient flexibility for quicker arm action, plus the fast-twitch ability to get said arm action, might equal 4-6 more mph. If you're a hitter and lack the hand-eye coordination to hit a baseball, you're screwed whether or not you're a bit quicker in the zone. But if you're a pitcher who is getting hit while throwing 86, and you can suddenly bring it at 92, you're more of a viable candidate for the majors.
Put alternatively, when you're a pitcher, you're the instigator ... if you already have decent control and deception, and can suddenly throw harder, you're instantly better. If you're a hitter and are suddenly quicker through the zone, I would contend that the extra "skill" required -- hand/eye coordination -- is a limiting factor as to the benefit that being on some kind of performance enhancer would allow.
The third, and probably the most important, point relates to steroids' ability to help someone recover more quickly from injuries and from bouts of exercise. The first benefit here should be self-explanatory. As for the second, steroids might, for instance, allow a player to go to failure in his weight training on a particular muscle group every three days, as opposed to every five. Put simply, they would prevent overtraining. This concept is easily extended to see how they could help a player not only stay stronger throughout the season, but also to train with weights throughout the season without having his muscles fatigued to the same extent during games. It's pretty simple ... player A is drug-free, and he would overtrain if he legitimately hit the weight room after the game six days per week. Player B would not, and he does work out that often. Player B can then get stronger, be less vulnerable to fatigue, etc. ... for a reliever, this benefit should be pretty clear. It's also a benefit for position players and starters.
It is for this latter reason that I'm amazed people keep trying to say something like "Barry Bonds has a workout regimen nobody else could maintain, so his muscle growth can't be from drugs." The fact that androgens enable quicker recovery between muscle exertion (and damage) is probably just as, if not more, significant than the factors I discussed in the first paragraph of this post. The very fact that he can, and does, go through those workouts, especially at his advanced age, is probably the biggest argument in favor of him having used, not against him having used.
Finally, I didn't allude to this in the introduction, but it's so common-sensical as to be overlooked ... steroids would help a guy maintain muscle mass over the haul of 162 games. If you ever hear about a certain player losing 15 pounds over the course of the season, and "losing strength," that is the kind of thing steroids could prevent. They alter the body's protein balance (nitrogen retention).
No, I'm not a sales rep for BALCO or Greg Anderson. I was, however, a personal trainer and pre-med student back in college. I did my honors thesis as an undergrad on "andro," so I've examined the mechanisms by which androgens work. I don't know everything about these kinds of things, and I lack first-hand experience, but all the research I've ever read would indicate that these drugs work in ways that help players in many ways besides simply making them stronger or more muscular.
Good stuff, eh? Makes me really appreciate guys like Hank Aaron and Willie Mays, who did it without being juiced. I wish I could have seen them play - it must have been something.
