Skeletal muscle mass in human athletes: What is the upper limit? - Abe - 2018 - American Journal of Human Biology - Wiley Online Libraryonlinelibrary.wiley.com
New data challenges upper limit of FFMI = 25 in men. Via Greg Nuckols:
"The *average* FFMI was 25.4 with a few people (albeit with higher body fat levels) in the 30s."
I've done some more research and I still stand by the old max FFMI = 25 rule, with the rare exception going up to 26-27.