Let’s face it: without steroids, it’s impossible to achieve a form like Schwarzenegger, Heath or any other athlete that we admire on the Mister Olympia stage. (Incidentally, this also applies to bikini and figure classes.) However, something can be achieved without the use of illegal anabolic substances.

If you take a look away from Mr. Olympia and other professional competitions towards Natural associations, you will find that only a negligible proportion of the (male) athletes are on stage with more than 90 kg. Those who do are mostly not defined enough, bigger than the average – or have just consumed steroids.

The regulations of the GNBF (German Natural Bodybuilding & Fitness Federation) give a first idea of ​​how much can be achieved naturally (without steroids). There it says:

“For the first time since 2014, the Fat-Free Mass Index (FFMI) developed by Harrison G. Pope (Professor at Harvard University) will be used as an admission criterion […]. […] For admission to the 11th GNBF German Championship, the value of the FFMI must not be higher than 26. Athletes who have an FFMI higher than 26 are not eligible to participate in the GNBF competition. ”

The Fat Free Mass Index (FFMI)

FFMI is a value that is calculated from height, weight, and body fat percentage. It provides information about body composition with regard to the ratio of fat and muscle mass.

Your FFMI you can here be calculated.

A value of 24 corresponds to a muscular (male) athlete. A value of 25 means an above-average amount of muscle mass. It is a high level that can only be achieved and maintained with serious commitment in the areas of nutrition and training, but also regeneration. In some cases, a value over 25 can be achieved without steroids – but these are absolutely exceptional athletes. 

Women have to use other values: In the literature, an FFMI of 21 is given as the natural upper limit.

Natural vs. supports: Eugene Sandow (left) is considered the founder of bodybuilding. He weighed around 85 kg with a height of 175 cm. With an estimated body fat percentage of 10%, this results in an FFMI of just over 25. Ronnie Coleman (right), eight-time Mr. Olympia, weighed 127 kg at his height at a height of 180 cm with an estimated body fat percentage of 4%, This corresponds to an FFMI of 37.6 (!). (Image source: https://broscience.co/the-difference-in-muscle-gains-by-a-steroid-user-vs-natural-bodybuilder/)

What does that mean in absolute numbers?

Lyle McDonald designed the following table based on the results of a study [1]:

Maximum lean muscle mass for steroid users and natural athletes.

In the study cited, a group of natural bodybuilders was compared to a steroid-consuming athlete. In the table, McDonald used – quite strikingly – the person with the lowest body fat and highest muscle mass percentage. As you can see, the steroid consuming athlete at 99.3 kg (219 pounds) is significantly heavier than the natural bodybuilder at 87.5 kg (193 pounds).

How much can I build?

Lyle McDonald uses a model named after him to show how much can be built up naturally in each training year. He points out that the term training year only refers to those years in which the training was actually sensible. In addition, factors such as age and genetics play an important role and of course gender. Women, therefore, have to halve the values ​​in the following table.

Possible muscle growth in kg per training year.

When these values ​​are added together, the total muscle size for men is approximately 18 to 23 kg, which can be built up naturally over the years (1 pound corresponds to approximately 0.5 kg). Other models come to a similar conclusion. You can read them in more detail here .

Conclusion

Admittedly, the fact that male Natural athletes bring 80 to a maximum of 90 kg on stage can be quite sobering – especially if you know pictures of athletes weighing 40 kg with 4% body fat. For the general public, someone who weighs 80 kg is obviously impressive – but probably less so for the ambitious competition athlete. Still, that’s the (bitter) truth. Many also believe that improvements in training and nutrition methods push the above limits ever further; however, according to Lyle McDonald and other researchers, this is simply a misconception.