"Losing" the type IIb fibers

[Chris Correia]

I've read the "use them or lose them' comments about the IIb "fast,explosive movement" fibers.

My question is, "Does one actually lose them, or do they just atrophy (for lack of a better term), and then, assuming the latter, they are redeveloped with the appropriate training (power clean, olys, jump squats, plyos, etc)?"

What's going on with the losing/regaining?

[Bill Hartman]

Training, even heavy or explosive training, actually causes a reduction in the percentage of fast-twitch, type IIB fibers (mostly due to conversion toward type IIA or AB). They are sometimes referred to "couch potato" fibers because folks who spend more time sitting on their asses actually demonstrate a higher percentage of FT, type IIB's than most trained individuals.

You can however take advantage of the delayed training effect by detraining after a period of heavy or explosive training where the percentage type IIB's tends to rebound past the original level.

Bill

[Chris Correia]

Thanks, Bill. But now I'm confused.

Why, then, does someone lose their quickness and explosive ability through lack of use (assuming that happens, as I've read) and then what happens when someone (re)trains with fast movements so that they can regain/redevelop that ability?

[Bill Hartman]

Don't forget that you're training the nervous system in regard to rate coding, recruitment, and synchronization to activate available motor units/fibers.

Someone who is more neurologically efficient but may have fewer fast-twitch fibers can out-perform someone who is fast-twitch dominant but at a lower level of training.

Bill

[Chris Correia]

OK, so the bottom line is that if I'm training for sports (martial arts, in my case), it neither matters what I've done or not done before nor where I'm starting at with speed/explosive ability; I should just shut up and train with some speed/explosive movements so I can improve those abilities. Fair enough?

[Bill Hartman]

It certainly matters what you've done as there will be a training effect associated with that.

To raise performance, identify strengths and weaknesses, raise abilities associated with weaknesses and optimize as many abilities as possible from neurologic, muscular, connective tissue, and technical issues.

Bill

[Chris Correia]

With weight training, I've done very little. I HAVE been regular since the first of this year (finally, after 44 years on this planet . . .). But I'm neither big, strong, nor fast.

I HAVE 5 months of Mike Mejia's Homegrown Muscle Men's Health routine under my belt. But I'm most concerned about athletic performance in taekwondo/hapkido. So, quickness/explosiveness and strength are my concerns. Right now I'm training a routine with largely 5x5 and 4x6 work, with each workout including one or two power moves (e.g., power clean, jump squat). On the right track?

And, I've just recently gotten Alwyn's martial arts conditioning book/CD combo. After my 6 weeks on my current routine, I expect I may be switching up to that.

[Bill Hartman]

Chris,

If you're that new to strength training, you won't need to get too "specific" at all. Focusing on raising strength levels while continuing your technical work should impact your performance quite nicely.

Some power variations and basic strengt ex. and protocols should be fine.

Bill

[Chris Correia]

Thanks for the feedback and explanations, Bill. I'm happy. Can I write a testomonial for you? [img]smile.gif[/img]