In Categories of Weight Training: Part 2, I bored you with some of the underlying physiology behind hypertrophy training In that article I discussed the issue of hypetrophy vs. hyperplasia as well as the idea that there are different types of hypertrophy (i.e. sarcoplasmic vs. myofibrillar), I also looked a bit at some of the underlying physiology of what stimulates muscle growth in terms of tension, fatigue and muscle damage (with some brief commentary about the hormonal response issue).
Today I want to use that as background to talk about hypertrophy training in more practical terms in the same way I did about metabolic training back in Part 1. I’ll start with some more general comments and then talk about intensity/rep range as a loading parameter, saving other aspects of hypertrophy training for the next parts of the series.
Now, compared to other types of training, it seems as if you see the greatest variety in what can stimulate or generate hypertrophy in terms of the different types of training that has been done or that seems to be “effective” on one level or another.
Basically, the phrase “hypertrophy training” covers a lot of ground and people have gotten bigger using approaches ranging from one or two sets of moderate repetitions to lots of sets of low repetitions to bunches of sets of high-repetition “pump” training. If you can conceive of it, someone has probably tried it or made it work.
Beating a Dead Horse
Now, at the risk of thumping an all too often beaten drum, part of the issue has to do with the use of anabolic steroids in bodybuilding (and other strength oriented sports). Steroids been around for at least 40 years (if not longer) and, as studies have found, can generate muscle growth (that is actual contractile tissue growth) even in the absence of training.
In one study for example, in young men (ages 18-35), doses of testosterone ranging from 25-600 mg/week led to a dose related increase in muscle mass (that is, more drugs meant more gains). In that study, the 600 mg/week group gained a whopping 18 pounds of lean body mass over 20 weeks with no training. And, factually, 600 mg/week is a fairly small dose compared to what people use these days (some drug gurus recommend as much as one gram of steroids per day).
In another study, subjects were either given steroids alone, training alone or steroids plus training. The steroids only group gained about as much size as the training only group with the steroids plus training group gaining essentially what the drugs alone plus training group had gained.
And, because of this, a lot of the strangest routines often appear to work because, in effect, drugs have made the actual training much less relevant. It’s not unheard of (though certainly not universal) to see drug-using bodybuilders fooling around with the lightest of weights and simply exploding in size (again, many top drug using bodybuilders are hellishly strong but that’s not the point I’m trying to make). But without the drugs this type of training is almost universally ineffective. Simply, many of the types of training that generate growth just fine when you’re taking drugs just do anything at all when you’re not. At least not for the majority of trainees.
I add that disclaimer since you can always find a small percentage of naturals (that I suspect have high natural testosterone levels in the first place which places them closer to folks using drugs in the first place) that seem to respond well to what many would consider “ineffective” training. The problem is that the folks focusing on that small handful tend to ignore that the grand majority make zero progress with that kind of training. At the end of the day, focusing on what works for the minority is less relevant to me than worrying about what will work for the majority.
And with that dead horse beaten, let’s start to look at loading parameters for hypertrophy training.
Hypertrophy Training Loading Parameters: General Comments
Irrespective of the steroid issue, hypertrophy training still tends to have the greatest variety of training methods and methodologies that all seem to “work” to some degree and there are a variety of reasons for this that I’ll try to touch on as I move through the series. At least one of them that I already talked about was the existence of distinct signalling pathways for hypertrophy that I discussed in Categories of Weight Training: Part 2.
Even if we only look at the three major pathways I described: tension overload, damage and metabolic fatigue; the existence of those distinct pathways alone could potentially explain how training ranging from high-repetition pump training (typically involving light loads and short rest periods which generates a heavy metabolic stress) to heavy strength oriented training (heavy loads and longer rest periods which focuses on the tension/damage end of things) can all “work” to one degree or another. Even the weird occlusion stuff might be mimicked by some of the old bodybuilder ideas of non-lock continuous tension training.
Now, it might be that the pathways are independent (impacting on different aspects related to growth such as energetic vs. contractile aspects of growth) or perhaps there is some type of synergy to be had by focusing on all of them due to overlapping or interacting molecular signalling pathways (either at the same time or in some sort of sequence).
Regardless, whenever you look at time-tested routines that seem to “work” for a majority of trainees (and I’ll talk about some of them later on), they always have some focus on each of the different pathways to at least some degree. There will be a tension component (heavy weights and progressive overload), there will be a fatigue component (volume, rest interval manipulation), and there will be a damage component (focus on lowering the weight).
Exactly how different programs integrate those components they do it is often variable but the components are always there. Some systems do it all in the same workout (my generic bulking program, Dante Trudell’s Doggcrapp, Borge Fagerli’s MyoReps), some stretch it out across a week (i.e. Daily Undulating Periodization of some sort such as Layne Norton’s Phat which has a heavy power day and a higher rep hypertrophy day), some sequence it across a larger mesocycle of 6-10 weeks (i.e. 2 weeks of pump work, 2-4 weeks of medium rep work, 2-4 weeks of lower repetition work) . For one related discussion I’d point you to A Quick Look at Some Popular Hypertrophy Programs.
Loading Parameters Part 1: Loading and Repetition Range
Since so many different types of training seem to “work”, hypertrophy training tends to have the largest range of defined intensities in the realm of sports science, being anywhere from 60-85% of maximum; this yields a repetition range of about 20 reps (60% 1RM) to 5 reps (85% of 1RM) or thereabouts. Basically the hypetrophy range falls in-between what I described as the depletion/metabolic weight training (60% 1RM or lower) in Categories of Weight Training: Part 1 and what I’m going to talk about when I get to maximal strength training (85% 1RM and up) a bit later on.
But as you can see that provides an extremely broad range of loading parameters from high rep pump work (perhaps 3-4 sets of 15-20 with 30-60 second rest) down to the classic 5X5 Program (typically done with 3-5 minute rests between sets and 80-85% of your maximum on the bar) with everything else in-between. And while the range of 8-12 repetitions (roughly 70-80% of 1RM) has been classically given as “the hypertrophy range” there is actually little to no scientific support for this that I’ve ever seen.
It’s cited repeatedly as being “‘proven” but if there is original research to support this, I can’t find it (when you see this value cited in something sciency, the reference is typically to a book by the same author which then refers another book which references an article which refers to a non-existing Biblical document based on a conversation by someone who may or may not have actually existed talking to their deity, etc; my point being that I’ve yet to see original research supporting this value).
Going off on a very random tangent, my gut has always told me that this is where the old 8-12 rep range came from although this may just be more of my nonsensical weight training numerology. Back in the day, a classic training routine was to do 3 sets of 10 for every exercise in a workout. I figure that lifters would get distracted and miscount their repetitions. Sometimes they’d do a couple less than 10 and sometimes they’d do a couple more. Over time they just split the difference and 8-12 (maybe we should call it 10±2) reps was born as the “hypertrophy” range.
More to the point, it’s clear that a variety of repetition ranges can lead to growth in the long-term so long as some type of progressive tension overload is applied over time. Some of this may represent the different molecular pathways that exist that trigger hypertrophy, some of it may represent the different “types” of hypertrophy I discussed in Part 2.
It’s worth mentioning that there might also be fiber type specific growth based on the loading parameters used. I haven’t talked about fiber types in this series so here’s a very short-course. Human skeletal muscle has two primary fiber types: Type I or slow twitch (or red) fibers which are more enduring and typically have less force production capacity and Type II or fast twitch (or white) fibers that generate more force but fatigue more quickly (and there are a ton of sub-types of each muscle fibers including IIa, IIc, IIx and I’m just not getting into that level of detail since it doesn’t matter).
Now, it’s typically been though that Type II fibers had the largest potential for growth for a variety of reasons but it may be that Type I can get a growth stimulus with sufficiently long enough sets (read: high repetitions). I touched on this in my series on Periodization for Bodybuilders. So in addition to any other effects (via differences in tension, fatigue, molecular signalling) that varying repetition ranges have on muscle growth, there may be fiber type specific effects at work
At the other extreme there is the idea that a sufficient volume of low-repetition work can stimulate growth (and yes I’m going to look at the recent publiciation by Brad Schoenfeld when this series is over). Which is as good a segue as any into a fairly tangential story, one of my early eye-opening experiences. Back at the dawn of recorded history (read: the mid 90’s) I took the USWF Club Coach Certification course; Wes Barnett was the lifter on the spot. I was fresh out of college with a fancy degree in kinesiology and thought I knew my stuff. I knew what caused growth, right?
In any case, I got into a discussion with one of the instructors and we got to talking about hypertrophy. How, I asked, did Olympic Lifters gain size when they needed it? He told me that, at most, Barnett might do a bunch of sets of 5 when he needed to put on size. What? How could that be when everybody knew that 8-12 was the hypertrophy range? I think it may have been that day that I realized I had a lot to learn.
But it made the early point to me that the idea that there is a single ideal repetition range for growth was incorrect. Clearly there was more going on. And between the possibility of different “types” of growth (again, discussed in Categories of Weight Training: Part 1) along with overlapping and possible interacting molecular pathways (as we know now), along with the potential for fiber-type specific growth responses it makes sense that a variety of different approaches could be potentially workable. It might also be that mixing different styles of training has an additive or synergistic effect.
And with that, I’m going to stop for today, it’s getting long and the next block of discussion (dealing with volume, frequency and exercise selection) will make a good next part. See you then.