# Hypertrophy: What causes it?



## musio (Jan 25, 2008)

http://hornfitness.com/2012/02/18/hypertrophy-what-causes-it/

Posted: February 18, 2012 in Strength Training



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Hypertrophy: What causes it?

I want to be clear right off the bat. I am a High Intensity Training advocate. I train myself in this fashion as well as my clients. However, within the HIT community there seems to be very dogmatic thinking where nothing seems to penetrate. My views may not be fully accepted. That's just fine by me&#8230;quite frankly I am not keen on the HIT clicks I have been seeing. Even so, understand thoroughly that I am NOT turning my back on HIT whatsoever. I am however, capable of being objective and believing there is more to the picture than just standard HIT.

What causes hypertrophy? It is a multifactorial process.

- Inroad (overload/ weakening of muscle)

- Increased tension (progression)

- Fatigue and/or hormonal resoponse

- Microtrauma (tearing of muscle fibers where repair and growth can occur)

No matter what the muscles MUST undergo Overload and it must be Progressive - period! There are different training protocols out there that produce results, but nonetheless this is the most important factor: Progressive Overload. This means one must overload the muscle and have enough recovery ability to go back in and progress from the previous workout. If this is not balanced you WILL NOT GROW.

It seems the degree of inroad, fatigue and microtrauma is dependent from person to person, to further complicate this, I will say muscle to muscle. Our muscle fiber make-up is a big determinant of how we will respond to strength training. If we are able to figure out our fiber make-up we can then address that specific muscle group with a protocol that would be advantageous for hypertrophy. There have been many whom have tried the standard HIT protocols that have not responded with muscular size, then there are those that do great with HIT. I myself do WONDERFUL! I have never seen such good results with strength AND size (when on a gain cycle that is). I can't exactly say why certain people don't see results on a strict HIT protocol. I am not there guiding each session and reviewing the next step. Perhaps they were doing something incorrect? Maybe they were doing everything right? Who knows. However, with that being said I firmly believe there is more to the picture than we think. There are people that respond better to the hormonal response (fatigue) with a slight higher volume protocol and some respond better to a higher load (microtauma) than others. At this point I can only imagine the HIT peeps are probably yelling at their computer wanting to punch me in the face for even speaking of more volume! Heresy! But let's not get any panties in a twist here, remember even Doug McGuff spoke of "Modest Intensity Responders" in Body by Science.

Heavier loads will typically be a lower rep range/lower TUL. For this example we will use the rep range of 5 - 8. With a lower rep range protocol, the use of FT fibers will be used very quickly, with little accumalyed by-products of fatigue. There is a sequential recruitment of fibers from ST to FT, but since the load is heavier the FT fibers will be recruited quickly. You will get some fatigue, but the load effect on the muscles will be higher. If load is heavy enough it will produce enough microtrauma where there will be inflammation, and satellite cell proliferation can occur. This is a process that repairs the torn muscle fibers, which increases the cross-sectional area of the muscle.

Lighter loads will be a higher rep range/higher TUL. For this example we will use a 12 - 15 range. Higher repetition exercises has been shown to increase testosterone, growth hormone (GH) and insulin-like growth factor 1 (IGF-1). These hormones are a HUGE factor in hypertrophy. More sets you do, the more output you have of these hormones; to a point that is. There is microtrauma that occurs in this rep range also, but it won't be as significant since fiber recruitment is based on effort. It's clear the effort at a higher rep range isn't as demanding as it is in a lower rep range (if the load is high enough).

For some people the same rep range protocol is NOT sufficient for every muscle. This I believe is predicated on fiber types in various muscle tissue within the person. The muscles that have a higher % of ST fibers, need a higher rep range to accomodate a thorough recruitment of those fibers in that particular muscle. Muscles that have a higher % FT muscle fibers respond much better to a heavier load and would be best to stay within a lower rep range/lower TUL. I am going to even further this and say the muscle fibers that have a higher % of ST will respond better to slightly more volume. This will increase more opportunities for the hypertrophic hormones to flood in and be utilized. If the rep range is high enough as stated, you will cycle through your ST fibers during the contraction process and barely touch the FT fibers. Your volume can be higher for this specific reason. Since ST fibers fatigue slowly and recover quickly, you are able to hit them with slightly more volume and they will recover quickly for the next workout.

Conclusion: More sets may be good IF the subject can't go to true volitional fatigue (failure) or may respond better to a higher rep range which would include more hormonal production . In both cases microtrauma would be at a higher level which may help adaptations to occur, especially if one can't produce the required intensity that is needed.

No matter what, whether your rep range is higher or lower, you must ALWAYS progress. You must always strive to either lift more weight, add reps or both. Progressive Overload is key to muscle growth. If reps or TUL is lower and you are growing in some areas and not others BUT you are STILL gaining strength in all your exercises - then re-evaluate and give this a try!

References:

Kraemer, William J.; Ratamess, Nicholas A. (2005)

Hormonal Responses and Adaptations to Resistance Exercise and Training

Sports Medicine, Volume 35, Number 4, pp. 339-361(23)Shoenfeld, B.; (2010)

The Mechanisms of Muscle Hypertrophy and Their Application to Resistance Training

Journal of Strength & Conditioning Research: Volume 24 - Issue 10 - pp 2857-2872Kwon, Y.S.; Kravitz, L. (2006)

How do muscles grow?

IDEA Fitness Journal. 3(2). 23 - 25

McGuff, D.; Little, J. (2009)

High intensity repsonders/ Modest intensity responders (The Genetic Factor)

Body by Science: Chapter 8 - p172-174

Bubbico. A.; Kravitz, L. (2011)

Muscle hypertrophy: New insights and training recommendations

IDEA Fitness Journal, 8(10).. 23-26


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## doggy (Mar 26, 2011)

any chance of having that in english?


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## Sharp161 (Jan 31, 2010)

Or with paragraphs?


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## Phenix (May 12, 2012)

I found it a good read


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## doggy (Mar 26, 2011)

Phenix said:


> I found it a good read


you would.


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## musio (Jan 25, 2008)

Formatting didn't copy but the first line in the post is a link to the page if you didn't see it..

It's a good read


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## HVYDUTY100 (Sep 4, 2010)

Training intense putting the muscle under stress with a sufficient weight with a controlled movement, taking it to failure sometimes on postive and negative. then going home eating a high amount of protein... jabbing some test and having a couple of days rest is what causes Hypertrophy for me


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## antbig1234 (Nov 27, 2011)

HVYDUTY100 said:


> Training intense putting the muscle under stress with a sufficient weight with a controlled movement, taking it to failure sometimes on postive and negative. then going home eating a high amount of protein... jabbing some test and having a couple of days rest is what causes Hypertrophy for me


paul you:lol: [email protected]


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## loganator (Mar 19, 2011)

Hypertrophy is optimal at 10 to 12 rep range more than that builds endurance rather than muscle and less than that causes strength gains rather than muscle alltho strength training has it's part because through strength training you can eventually up your weights within the 10 to 12 hypertrophy range and big weights = big muscle gains so long as you are eating enough carbs protien to fuel the growth that is the biggest issue is diet because muscle will not grow from effort and gear without food FOOD ! FOOD ! FOOD ! lots of food ..... Haha sorry but just come off 19 week diet lol ,

When you eat will play a big role too as eating post workout the muscle is hungry and eating before bed makes you store fat ,

Simple really no need for jargan and bollocks just train hard and eat well


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## ladcrooks (May 15, 2013)

doggy said:


> any chance of having that in english?


workout with a weight your body is not accustom to :laugh:


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