Muscle Fiber BS: More Guru Marketing

2009 August 14

By Matt

I’m sitting around minding my own business today when I come across another guy hawking the newest most magicalest program ever that will fix all your problems and make you a champion and pay off your credit card bills.

I watch the guy’s video on YouTube, and there are some glaring mistakes in his representation of the science. So I chimed in on the comments, pointing this out to him.

What happened next, well, you can read for yourself:

http://www.youtube.com/comment_servlet?all_comments&v=XX8gn0c31vk

My original comment:

You know I get that you’ve got an idea to put out there, and I’m not saying that your programs are going to be bad, but I really, really wish you’d not bring “fiber types” into it.

Your explanation of the science there was way off. Hybrid fibers (co-expressing MHC isoforms) really aren’t indicative of performance per se. It’s neurological activity that determines that. Fibers in turn shift to reflect behavior. In other words, the MHC content (“fiber type”) is determined by the CNS and training.

Response:

Wow PowerManDL! You’re pretty smart man.

You say, “It’s neurological activity that determines that.”

Simple minded me says, “ATTITUDE”

You say, “Fibers in turn shift to reflect behavior.”

I simply say, “ATTITUDE”.

You say, “…is determined by the CNS”

I just say, “ATTITUDE”

Hmm? Do you think I should use bigger words and more complex phrases to explain?

Now I can’t go into long-winded diatribes about the science in YouTube comments, but let’s put it this way:

The CNS is what controls your muscles. Muscle fibers are grouped together into motor units, which are linked to the CNS by a motor neuron. All the fibers in that motor unit “bundle” are all activated when that neuron fires. These motor units all activate under different conditions depending on the resistance you’re trying to overcome, and they all have different fatigue tolerances (that is, the ability to remain active over time). It’s correct to think of activity within the muscle as being a function of motor unit activation.

Muscle fibers on the other hand are not really relevant from a “function” standpoint. It’s the motor unit that is of concern to us – the fiber’s just like a light-bulb being switched on. It’s the switch over on the wall that actually controls the process.

Muscle fibers are plastic, meaning their characteristics shift according to how they’re used. Form follows function.

When we get into a discussion about typing fibers as type I, IIa, IIx, or IIc (which is a hybrid expression), we’re talking about specific proteins being expressed in that fiber. But here’s the catch: those proteins express because of how the fiber behaves.

You have no more control over how your fibers express myosin heavy chain (the protein that we use to classify muscle fibers) than you do over how you train. The exercise you choose to do is what ultimately determines how your fibers “look”. If you spend a lot of time with heavy weights, expect a lot of fibers expressing MHC type IIa. If you do a lot of running, expect to find a lot of type I. It’s a matter of specificity.

Not only is this ignored, it’s actually twisted into some magical “type III” fiber that has never, ever been mentioned in scientific literature. Further, we’re actually expected to believe that fibers co-expressing different MHC isoforms (hybrid fibers) are some magical solution to your training problems – and that this comes about because of ATTITUDE!

I point this out to the guy, not even knocking his programming per se (because I haven’t seen it); I don’t know if his training programs are good or not. My issue was with the mistakes in the science, which I can and will back up with peer-reviewed research.

Instead of thinking “hmm, maybe I shouldn’t go spread voodoo all over the place”, what do we get? Defensiveness. Rationalization.

This is why the fitness industry is messed up, folks. This right here.

There’s no respect for science, but people want to talk about science. There’s no critical thinking. No evidence-based approach. And if you have the audacity to call somebody out for a line of horseshit, you’re  branded a “hater”.

You know what, though? I am a hater. I do hold it against you for promoting misinformation and for claiming expert status when you clearly are not. I do hold it against you for lying to people to get another income stream.

If you want to make money, fine. I don’t really hold that against you. What I do take real issue with is people that don’t even take the time to understand what they’re talking about. It’s not hard to be factually correct.

If you don’t understand the science behind it, hey, that’s fine man. Just leave it out. I’d have way more respect for people if they didn’t try to act like experts on matters they aren’t familiar with.