Optimists say that with enough hard work, patience, and the right nutrition, you can get as big and strong as you want.

That it’s impossible to set a hard ceiling on your potential for whole-body muscle gain.

To support this rosy outlook, they point to the physiques of top-level bodybuilders and studies on elite college athletes, who they claim achieved their freakish size without steroids.

Others claim all it takes to max out your size and strength is a few years of proper training and nutrition, and after that you’re stuck with what you’ve got, regardless of how hard you work.

Who’s right?

I invited one of the godfathers of the evidence-based fitness world, Lyle McDonald, back on the podcast to delve into the science of steroids, genetic potential for muscle gain, and the fat-free mass index (FFMI).

In this episode, Lyle and I chat about what FFMI is, where the idea that 25 is a “natural cut off” came from, why sumo wrestlers and powerlifters reach higher FFMIs than this, “fake natty” red flags, and more.

Let’s dig in!

Time Stamps:

13:19 – What is FFMI?

21:27 – Why is a normalized FFMI of 25 a likely ceiling for most people?

52:14 – What is your opinion on the studies on limits with college athletes?

01:15:16 – Would you agree that a FFMI over 25 is a red flag for steroid use?

Mentioned on The Show:

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Lyle’s Website

Lyle’s Store

What did you think of this episode? Have anything else to share? Let me know in the comments below!