Intensity and hypertrophy

[Bill Hartman]

The role of resistance exercise intensity on muscle fibre adaptations.

Fry AC.

Human Performance Laboratories, The University of Memphis, Memphis, Tennessee 38152, USA. afry@memphis.edu

Although many training variables contribute to the performance, cellular and molecular adaptations to resistance exercise, relative intensity (% 1 repetition maximum [%1RM]) appears to be an important factor. This review summarises and analyses data from numerous resistance exercise training studies that have monitored percentage fibre type, fibre type cross-sectional areas, percentage cross-sectional areas, and myosin heavy chain (MHC) isoform expression. In general, relative intensity appears to account for 18-35% of the variance for the hypertrophy response to resistance exercise. On the other hand, fibre type and MHC transitions were not related to the relative intensity used for training. When competitive lifters were compared, those typically utilising the heaviest loads (> or =90% 1RM), that is weightlifters and powerlifters, exhibited a preferential hypertrophy of type II fibres when compared with body builders who appear to equally hypertrophy both type I and type II fibres. These data suggest that maximal hypertrophy occurs with loads from 80-95% 1RM.
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Bill

[Eric Cressey]

Fry is a great reseacher (a former Kraemer PhD student), but I must admit that I'm a little surprised that he didn't at least mention the impact of training age in this abstract. Give me an untrained grandmother, and I could get hypertrophy by just having her pick up a pencil and put it down a few dozen times!

[Bill Hartman]

Originally Posted by Eric Cressey

Fry is a great reseacher (a former Kraemer PhD student), but I must admit that I'm a little surprised that he didn't at least mention the impact of training age in this abstract. Give me an untrained grandmother, and I could get hypertrophy by just having her pick up a pencil and put it down a few dozen times!

He does mention the limitations in the review that all subjects in the reviewed research were untrained (but not grandmothers ). I am a bit surprised that with untrained subjects that the intensity was as high as it was to result in maximal hypertrophy. Also keep in mind that he was only looking at the relationship to intensity and there were a variety of protocols and execises used.

I found a copy here

http://www.sergiogregorio.com. br/artigos/Fry%20SportsMed%202 004.pdf#search='Sports%20Med%2 02004;%2034%20(10):%20663679'

Bill

[Mike Robertson]

So lifting heavy things actually makes you bigger AND stronger? (Note heavy internet sarcasm here)

When I was at BSU he was looking into better explaining bands/chains; do you know if he ever published any of that stuff?

MR

[Eric Cressey]

If he did, I haven't seen it....and Lord knows a study like that is needed. The Ebben and Jensen one from Marquette a few years back made me want to gouge out my eyes with hot pokers. The study design was atrocious.

[Darkmind]

This is a very interesting study to say the least, but I do have a couple questions about it.

How many sets do they perform? How many reps? I mean, I've heard that 10x3 @ 80% 1RM is a great way to increase type IIb muscle myofibrillar hypertrophy (or something like that.... look at me, I'm stupid!).

[Jimmy Smith]

very nice read