Genetics play a major and unequal role in muscle development; it is therefore unrealistic and counterproductive to compare your physique to that of others, as some individuals possess superior biological predispositions for muscle gain.

noli's read

This observation is solidly supported by research in exercise physiology, notably studies on 'responders' and 'non-responders' to training (Hubal et al., 2005, observational/experimental study). The literature confirms that the variability of muscle growth is largely influenced by genetic factors, such as satellite cell density, baseline hormonal levels, and myotendinous structure. Jeff Nippard’s statement is therefore scientifically grounded: genetics impose different biological ceilings for each individual. This is not an exaggeration, but rather a necessary perspective to avoid the comparison biases often observed in the fitness community. The idea that one cannot always achieve the physique of another through hard work alone is corroborated by data on the heritability of physical traits. In summary, recognizing these genetic limits allows efforts to be directed toward personal progression rather than inaccessible standards.

the sources

No named source held this one up — that absence is part of the verdict.