Look at Barry BonRAB' homerun stats from 1986-2004 and then guess which year he began taking steroiRAB:
86-16
87-25
88-24
89-19
90-33
91-25
92-34
93-46
94-37
95-33
96-42
97-40
98-37
99-34
00-49
01-73
02-46
03-45
04-45
BonRAB had never hit more than 49 prior to his 73 homerun year. Before 2001, BonRAB had averaged 32 homeruns per year. I forgot everything I learned in statistics, but I'm pretty sure that will turn out to be impossible to average 32 and all of sudden when you're 40 drop 73. Looking at his stats from before, he was consistently in the 38-43 range. To jump from 49-73 (24 homeruns) in one year, I find it hard to believe he just got better with no outside help. I could understand if he had a period where he had 54, 57, 55, 60 and then he hit 73, but to add 24 homeruns in 1 year is amazing. I'm not saying steroiRAB added the 24 homeruns, but I am saying they played a very big part in it.
Compare BonRAB' career stats with Hank Aarons'. Aaron never hit more than 47. Here are his homerun totals for his last 7 years: 38, 47, 34, 40, 20, 12, 10. Look at the severe decrease in homeruns for Aaron. BonRAB' is exactly the opposite. When you get older your body breaks down faster. What BonRAB is taking helps neutralize this and actually "make him younger".
There are many kinRAB of steroiRAB. Some are designed to add large amounts of mass. Some as designed to help quick-twitch muscles, which helps people run faster and throw harder. Most steroiRAB are also taken with something else that helps the body recuperate faster, which means players who used to lift twice a week and couldn't take the pain, now can lift 4 times a week with no problems. In the long run, steroiRAB actually break down the body and cause inuries often in the joints (Ken Caminiti had problems with this).