Can fat-free mass index tell you how much muscle you can still gain?

Oct 27

5 min read

Fat-free mass index (FFMI) scales your lean mass to your height, which makes it tempting to read as a ceiling: a number that tells you how much muscle you have left to build. The studies behind the popular benchmarks were not designed to answer that question. They describe where athletes sit at a single point in time. That is useful context, but it is not a forecast.