I utilize a low intensity, higher volume form of training and have I believe read in the past that this form of training which produces strong local fatigue and metabolic buildup causes a shift toward 2A fibers. I had a reference to a related study but cannot seem to find it. Has anybody on this forum read or know of this research? Thank you.
Any sort of activity will convert Type 2B fibers to Type 2A. But you cannot shift from 1 to 2. If you stop lifting or become sedentary, the 2A fibers convert back to 2B. Type 2B fibers are the default fibers and we are not sure why is it so.
Thank you administrator for your response. From what I have read in different studies, biopsies of bodybuilders show that type 2A is the prominent fiber type with 2B being a minor factor. I wonder if one can create the proper anabolic training environment using lower loads performed in a more stimulating manner to muscular failure? I currently use a modified form of Matrix Training which in theory provides stimulus not so much through loads but by lifting loads from different joint angles and adding different rep patterns and isometric holds. The variety of different movement patterns(could call it muscular confusion) definitely produces new stimulus with a significant “pump” response.
I am looking for a study that shows the shift to type 2A in the use of lower load resistance training to muscular failure/fatigue. I had one but somehow lost it. Any help would be appreciated.
Thank you Anatoly, but no. I have the tissue composition study somewhere. There is research that showed that fatigue in lower load resistance training caused a shift to type 2A fibers rather type 1. Some believe that lower load lifting cannot produce hypertrophy because the fatiguing high rep programs shift to the usage of type 1 which is not thought to produce much in way of muscle growth.
It is physiologically not possible to shift from Type 2 to Type 1 in humans at least. I have seen it in rat studies where they have rats running for 4-5 hours a day and electro stimulation and fibers shifting from 2 to 1.
Sorry for the poorly worded posting and I hope my future attempts are better produced. Perhaps a better way of asking, are there studies that have looked at humans and evaluated what fibers are primarily utilized for resistance training that have a longer time under tension and or higher rep range(20-30)? Also, under the theory of the “Size Principle”, if the working load is taken to failure whether it be 40% or 80% of 1RM, would the same fiber type be recruited? Thank you.
Size principle has been discussed previously on board and you have Anoop’s article on a main site on occlusion
There is also an article on “high/low reps for growth” on a main site
Yes.If you take a load to failure, you will recruit the Type 2 fibers. But there might be point where even if Type 2 fibers are recruited the load is too low or the muscles have crept into endurance adaptations zone for any appreciable muscle. And it could be different for upper body and lower body and also for beginners and trained.
That one looks at data from twin studies and studies comparing limbs in the same subjects and they find a variation that cannot be accounted for just by the inherent variation in the methods, they also cite some experimental studies.
Also, with combining explosive and regular resistance training, a shift from type I to type II has been seen:
Different effects on human skeletal myosin heavy chain
isoform expression: strength vs. combination training http://jap.physiology.org/cgi/reprint/94/6/2282
Thanks for the studies Karky. Perhaps from your review of the literature, if one does a combination of longer isometric holds at varying points and eccentric accented partial reps, would this constitute a viable hypertrophy program with loads at the 50% of 1RM range?
Anatoly, I am experimenting with a training protocol that is different than Matrix. I am looking for research material that has used elements of what I am working with, isometrics, eccentrics and partial repetitions that may improve the program.
Let me apologize, my remark was unappropriated
Keep us updated with your search, I’m also interested in any method of training that gives results without high loads. I’m 42 and already think forward.
Thanks for the studies Karky. Perhaps from your review of the literature, if one does a combination of longer isometric holds at varying points and eccentric accented partial reps, would this constitute a viable hypertrophy program with loads at the 50% of 1RM range?
I haven’t read anything specific about this, sorry.
