A study from the University of Medicine and Dentistry of New Jersey set out to determine if a commonly used soy protein supplement exhibits biological activity. Researchers studied healthy male volunteers, aged 18 years or older that were in good health. They consumed two scoops of pure soy protein powder daily for 28 days. It turns out soy protein powder actually decreased testosterone levels, thanks to the estrogen. This same estrogen may also cause testicular shrinkage. The good news is, when study participants discontinued the soy protein powder, testosterone levels increased within two weeks.
He came up with it after years of studying steroid users in Boston-area gyms and comparing them not just to non-steroid users in the same gyms, but also to bodybuilders from different eras. For a 1995 study, Pope and his coauthors estimated the FFMIs of Mr. America winners from 1939 to 1959, before steroids were readily available. The group includes future B-movie star Steve Reeves, whose physique was so iconic that he was name-checked in The Rocky Horror Picture Show . The average FFMI was . (One of the highest was George Eiferman, Mr. America 1948, with a FFMI. His upper body was later the model for George of the Jungle, a 1960s cartoon character.) Even today, with all we’ve learned about training and nutrition, an FFMI in the mid 20s is still considered the ceiling for natural bodybuilders. Anything above 26 or 27 is suspect.