In one sentence
An estimate of the most lean mass a person training without drugs could carry at their height: a ceiling to think against, not a goal.
What it is, and what it is not
Vitality Tracker takes the ceiling from research. In 157 male athletes, the fat-free mass index (lean mass divided by height squared, adjusted to a height of 1.80 m) of those who had never used steroids ran up to a well-defined limit of 25, and twenty Mr. America winners from before the steroid era averaged 25.4 (Kouri 1995). VT turns that limit back into kilograms for your height: about 79 kg of lean mass for a man of 178 cm. Kouri measured men only; the ceiling of 22 that VT uses for women is the figure commonly given for women and does not come from that study, so take it as the rougher of the two.
Berkhan's rule
Until October 2026 VT used the rule of thumb the strength coach Martin Berkhan drew from the competition-day weights of drug-free bodybuilders: height in centimeters minus 100 is the most you can weigh, in kilograms, at a stage-lean 5 to 6 percent body fat (Berkhan 2010). It is a practitioner's observation, not a study, it is for men only, and it is the stricter of the two: for a man of 178 cm it allows about 74 kg of lean mass to Kouri's 79. VT moved to Kouri's ceiling because Berkhan's rule has no version for women.
Why show it at all
Because members who lift ask, and a rough ceiling with its provenance stated is better than the numbers that circulate without one. It says what years of training can plausibly add; it is not a goal, and most people are well served long before they approach it.
How Vitality Tracker uses it
In the Body Composition panel, beside FFMI: the weight you would have at the ceiling at 15 percent body fat, with 5 and 10 percent a tap away. Nothing scores on it.
How far to trust the number
A ceiling from one study of male athletes, applied to you through your height; take it as a range of several kilograms, not a point, and not as a verdict on anyone who goes past it.
Sources
- Kouri EM, Pope HG, Katz DL, Oliva P. Fat-free mass index in users and nonusers of anabolic-androgenic steroids. Clin J Sport Med 1995;5:223–8. doi:10.1097/00042752-199510000-00003
- Berkhan M. Maximum muscular potential of drug-free athletes. Leangains, 28 December 2010, updated 31 December 2010. leangains.com.