How To Tell A Natural Bodybuilder from Steroid User

People always ask for ways to tell if someone is a steroid user or not and I stumbled upon a very simple formula today that research seems to indicate is a very accurate indicator. Its the Fat Free Mass Index (FFMI). The research cited below found that the upper limits of FFMI in natural bodybuilders was 26. In other words, if the calculated FFMI is over 26 then they use steroids. As a reference point, Steve Reeves FFMI was 25.7, mine is 23.9

Here is the formula for FFMI:
FFMI= LBM/(height*height) + 6.1x(1.8-height)
Note: height in meters. Lean Body Mass (LBM) obtained from my body composition calculator and stated in kg.
All the research showed was that if the FFMI is over 26, then they are a steroid user. Just because someone has a FFMI under 26 does not mean they are natural! It in no way eliminates the need for drug testing as I’m sure there are hundreds of thousands of steroid users with FFMI’s under 26. The basis for this formula is that there is a upper limit of muscle mass, the only way to exceed it is with steroids.
This forumla and these findings comes from research done by E.M. Kouri et al. back in 1995. The title of the article was “Fat-Free Mass Index in Users and Nonusers of Anabolic-Androgenic Steroids” published in the Clinical Journal of Sports Medicine (1995):223-28
I was reading an old book in my library titled “The Adonis Complex” by Pope, Phillips, and Olivardia when I stumbled on this great formula.

11 thoughts on “How To Tell A Natural Bodybuilder from Steroid User”

  1. Just curious… if your wrist size and ankle size are very large and you have a large frame, then can you exceed 26 without steroid use? I am asking because currently I stand at 5″8′ and have a lean mass of 167 (according to dexa). This puts my FFMI at 25.89, which is very close to 26. However, according to a formula on lean mass potential based on frame size of natural bodybuilders my height, I can supposedly put on a little more than 12 more pounds of lean mass (also, is it possible that some of this lean mass is attributed to high bone density? in my age group, according to the dexa scan, my bone density topped the graph out completely in the 99 percentile and said I was 5x the standard deviation of bone density in my age group). I just want to know if I am currently at my limit for maximum lean mass potential, or if it is possible to break this barrier since research is an observation of a sample, and there may possibly be outliers. It just looks like I can get more development in my chest and arms. I look rather small for someone of my stature.

  2. scooby your awesome and I appreciate all that you have done for this sport so much, I am annoyed because of claims you have done roids. Will you set the record strait once and for all. I have this in my head I can be as big as you one day. If its never going to happen without steroids I would sure like to know. A guy in my class says you have done them. I don’t know where he got his info from. Flex for life website or something like that.??

  3. I calculated my FFMI at 32. I have never taken steroids but have been lifting weights for 25 years. Various individuals in my family have won bodybuilding competitions naturally so I know my genetics are good but that score would suggest I am a genetic freak and I doubt that. My calculations all appear to work out correctly but is the FFMI a good indication of steroid use? Doesn’t appear to work for me and the study does seem quite dated, is there any new research on FFMI???

  4. at david, the reason is because you are doing too many reps if you want to see your muscles grow, at that many reps you are doing muscle endurance. put a weight on your back or a backpack with some weights or whatever you find works best, and do sets up 8 reps. increase the amount of weight when you can easily do 8 reps and keeping increaseing it as such, do this and you will see your pecs tris and delts become much more developed

  5. Only 18.5 for me. I'm working since 2010 and did't gain any visible muscle. Started with 5 pushups, now 250 in 8 sets … I don't really understand why I'm able to do a lot more reps but don't look stronger ^^

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