Jeff Nippard examines the scientific limits of natural muscle building by analyzing historical bodybuilders from the pre-steroid era and modern research. Using the Fat-Free Mass Index (FFMI) from a landmark 1995 study of 157 subjects, he identifies that most natural lifters plateau around an FFMI of 22-25, with rare individuals reaching slightly higher. Historical examples like Steve Reeves (1947) and Eugene Sandow (1897) demonstrate impressive natural physiques achieved before steroids existed. The analysis includes realistic muscle gain rates showing most men can expect 17-42 pounds of lean mass in their first three years of training, with significant genetic variation affecting individual results.
