Muscle Fibers - 2 Critical Questions
 

1)ABCBodybuiling is saying in one of their pdf articles that muscle fiber hyperplasia can be achieved through slow (and painful :D) negatives. That means that, for example, if I am training with very low reps (let's say 3), with slow negatives, there will be hyperplasia in type 2b muscle fibers and if i am training with very high reps and emphasize the negative phase, muscle hyperplasia will be present in type 1 muscle fibers?

2)Are type 2b muscle fibers actually the one that have the most potential for maximum size...in all people?

thnx 4 replies

I am very confused but this seems interesting :P lolol. Either way you should always be doing slow negatives for more burn, especially your final negative.

A true statement as negatives introduce (among other things) fibrous stretch. For those that are unfamiliar with these terms, Hypertrophy refers to an increase in the size of the cell while hyperplasia refers to an increase in the number of cells or fibers. A single muscle cell is usually called a fiber.

Just from an educational stand-point, i would say - Not necessarily. Type 1's are slow twitch and high O2 fibers making them very fatigue resistant. I would think that this alone means low ratios to stretch and hyperplasia. But ive made a note to look into this more closely. It's a good question.

More... Type 2A and 2B, and yes - In all living organisms that have skeletal muscular systems, and IF body type, gender, and genetic composition allowed for it. i.e Females don't bulk... unless that female happens to be a hen. (strange thing about chickens... female hens bulk... male roosters don't.)

Generally endurance athletes are training type 1's (runners for example). Type 2A and the type 2B muscle fibers should be your priority. Continually mixing up negatives, drop sets, super slow reps as well as heavy straight sets assures that you are recruiting both the A and B side of the fast twitching muscle fiber types.

** disclaimer: I'm not a body builder. I'm a PT with both educational and practical interests in physiology, kinesiology, and sport.

Just to add to wildgrl's excellent response, I wouldn't stress over what fiber types are undergoing hyperplasia if in fact that is occuring....just be happy it is. That said, based on the animal study that documented hyperplasia, stretch position exercises are the best way to attempt it.

Train hard and train smart, don't sweat the minutia.