Manipulating Training Variables (Part II) – The Principle of Specificity

It’s a long one… Have some highlights! (TL;DR)

  • Training specificity is a measure of how similar the things you do in training are to the final outcome (goal) you are training for.
  • The higher the specificity of training, the more that training will translate to progress towards your goal (at least in the short term).
  • Depending on goals, maximizing specificity all of the time could leave gaps in a lifter’s development.
  • There are several training variables that can be adjusted on a spectrum from general to specific including movement selection, total volume, intensity, frequency, set/rep schemes, rep speed/execution, and training density. 

In part one of this series, we talked about the fallacies of muscle confusion and why the optimal response to hitting a plateau is not necessarily to just switch all of the exercises you are using. Today, as promised, we’re going to delve into several alternative ways we can adjust the stimulus we are providing to our bodies through training while still building towards our goals and not losing touch with the specific task at hand.

I’ll say right off the bat that I’m not advocating that lifters never train new movements (in fact, subtle variations can be really useful; more on that in a minute!). The average trainee can find good success and also escape from monotony by rotating things occasionally. Even if you are a competitive powerlifter or weightlifter, you will still probably find that their are non-competition movements you can focus on (probably more so during your off season) that will help you address weaknesses or other issues to make you a better lifter overall. That all being said, I’d recommend sticking to your guns long enough to make some serious progress with the core movements you are most interested in. The exact amount of time this will be depends on the lifter and their exact goals for a certain training strategy, but for our purposes here, let’s say as a general guideline that whatever goal you set will hopefully be worth at least a couple months to you before you decide you want to change anything too drastically.

Right, then.

The What and Why of Specificity

When it comes to getting stronger on a certain lift (I’m going to use the barbell back squat as an example throughout this article to keep things simple(r)), building more muscle, improving your endurance, or pursuing any other training goal, the principle of specificity, or the idea that adaptations are specific to the nature of the applied stimulus, is vitally important. In this context, training specificity basically refers to the level of similarity between what you are doing in training on any given day and what you are training to be able to do at the end of your training plan. Let’s say the goal is to enter a powerlifting competition. When it comes to your squat training, the highest level of specificity you could achieve would  be doing a 1 rep max with your competition gear, competition stance, etc. Anything that diverges from that will be less specific to your final goal of hitting the highest 1 rep squat max you possibly can. For instance, doing sets of 3 would be less specific (in other words, more general). Doing sets of 5 would be less specific than that. Doing sets of 5 with a different stance would be less specific still. You get the picture.

So what? Am I saying that powerlifters should never do anything but train 1 rep maxes of the big 3 lifts? Definitely not!! But more on that in a minute. The reason we want to be conscious of specificity in our training is simply that the less specific—or rather, the more general—our training becomes, the less directly that training will transfer to our final goal. For example, training the crap out of the leg extension machine at the expense of training your squat probably won’t make you much better at squatting. But that’s not to say that more general (less specific) training doesn’t have it’s place.

In the case of a powerlifter, there are several benefits to be gained by venturing away from 1 rep maxes (the pinnacle of specificity in this case) in training. For one thing, all other things held equal, a bigger muscle has the potential to be a stronger muscle, so our hypothetical powerlifter will want to train in higher rep ranges at least some of the time to promote hypertrophy and increase his/her strength potential (more on this in a minute!). On top of that, there are several important things like work capacity (in a nutshell, how much training volume you can handle without falling to pieces, either in the gym or recovery-wise), motor patterning and movement quality, and the psychological effects of doing nothing but training super heavy every single day to consider.

To summarize, specificity is important for working towards our goals, but there are also significant rewards to be reaped by (somewhat) more general training. So how exactly do we manipulate specificity, and how general is too general? Well (and I feel like you are probably getting used to hearing me say this by now)… It depends!

alan blackjack hangover

Training Variables

To help us systemically discuss ways to shift our training along the spectrum from specific to general, I’ll discuss a few (7, I guess) variables that can be easily adjusted to suit one’s goals when laying out a training plan:

Movement Selection – This is simply the selection of exercises you choose to program into your training. As mentioned above, selecting the exact exercise with the exact setup you plan to use for your final goal would constitute the highest level of specificity. Any change from this will make the movement somewhat more general. For a wide stance, low bar back squatter who uses knee wraps and a belt in competition, doing this exact squat would maximize his/her specificity. Removing the knee wraps or the belt would make it more general. The same goes for switching to a more narrow stance or a high bar position. Switching to, say, a front squat would be even more general yet.

As to how general becomes too general, it really depends on the lifter and their goals. I wouldn’t recommend that someone trying to maximize their back squat power focus on nothing but leg extensions and leg curls at any point in their training, but focusing on a movement like front squats or safety bar squats could certainly be beneficial during a more general phase of their training. Of course, this depends largely on where they actually need to improve to bring up their back squat strength.

How well improvements in one movement carry over to improvements in another movement (e.g. how well improving your deficit deadlift strength improves your deadlift strength from the floor) can be pretty dependent on the individual, so it’s something you can experiment with as you go forward with your own training. As a general rule of thumb, though, the less a movement resembles the movement you are trying to ultimately build, the less carryover you can probably expect to see (i.e. getting really strong on the bench press probably won’t help you much with deadlifting more weight).

In short, I’ll just recommend that you strive to: 1) have a reason for including each movement that you select in your program, and 2) avoid falling into the trap of hopping rapidly from exercise to exercise, as discussed in part one of this series.

Total Training Volume – Training volume is normally defined as the total amount of work—although some also just define it as the total number of sets and reps—accomplished in a training session. This is calculated as: sets x reps x weight used (as some of you may note, this is not technically a calculation of work, because we are not accounting for the distance the weight travels each rep, but for an individual repeating a movement, this will be fairly consistent, so our calculation is at least proportional to actual work).

It has been pretty well established that doing multiple sets of an exercise is superior for inducing both hypertrophy and strength gains when compared to doing a single set. Furthermore, up to a certain point, these effects seem to be dose-dependent (i.e. doing more volume leads to more gainz), although as I’ve discussed in previous articles, there is a limit to how much volume you can handle before you begin to work yourself into a hole, or overreach.

Before we delve more into the idea of manipulating volume, I need to introduce the next training variable:

sumo deadlift

Training Intensity – No; this isn’t a measure of where you fall on a spectrum from listening to Katy Perry to listening to Slayer while you train. Intensity in this context is simply intended to refer to how much weight you are using relative to your 1 rep max (% of 1RM) in training. As I’ve mentioned in the same previous writing I linked just above, the best way to get better at moving heavy things is to move heavy things (i.e. train in higher intensity ranges).

This study from Dr. Brad Schoenfeld’s lab caused a bit of a stir recently with the finding that there was no significant difference in the changes observed in muscle thickness (specifically biceps brachii) in trained subjects who participated in volume-equated training regimens that either utilized a traditional 3 x 10 (3 sets of 10 reps) bodybuilding approach with 90 second breaks between sets or a more powerlifting-oriented 7 x 3 set/rep scheme with 3 minute breaks for each lift trained. While there were no differences in the observed changes in muscle thickness, the 7 x 3 group did demonstrate a significantly greater increase in 1RM bench press strength (as well as a statistically non-significant increase in 1RM squat strength), suggesting that higher intensity training is superior for strength development and, at least in this case, not inferior for hypertrophy. Now, it is definitely worth noting that in this study, the 3 x 10 group was doing a body part split (each body part worked once per week), whereas the 7 x 3 group did full body workout each day (and thus had 3 times greater training frequency, although total volume was equated). In my mind, this is a pretty big potential confound, but I’ll discuss more about training frequency in a minute.

Returning the focus to training intensity for the moment, the main take-away is that training at higher intensities is optimal for building strength (and—at least up to a certain intensity threshold where only a very small number of reps can be performed—probably not drastically inferior for hypertrophy), but the caveat is that the higher we raise intensity towards 100% of our 1RM, the less total amount of volume we will be able to complete and successfully recover from.

So, if the goal is hypertrophy, intensity can be decreased to allow for more total training volume, although there is a limit to how far it is prudent to take this exchange. While the exact threshold is pretty inconsistent throughout the literature (I’ve seen ranges from 50-70%), it seems pretty well established that at a certain point, there is a drastic decrease in hypertrophy adaptations to weight training once intensity drops too low (although techniques like blood flow restriction training can counteract this effect, but again, that’s a discussion for another time). For the sake of everyone’s sanity, I’ll give a number and recommend using at least 60% of your 1RM when the goal is hypertrophy.

If the goal is strength, we want to increase our intensity and, out of necessity, allow the total training volume to decrease as needed to keep us within our ability to recover from the stresses placed upon our bodies by the training.

Training Frequency – This refers to how often you train a particular muscle group or movement pattern (e.g. squatting 3 times per week). Higher training frequency can be pretty beneficial for several reasons. For one, you’ll get more consistent reinforcement of (hopefully desirable) motor patterns. You know the old adage, practice makes perfect. In short, if you want to get good at, say, squatting, one of your best bets is to practice squatting several times per week.

Improvements due to learning to perform a movement are one thing, but another hotly debated topic in the lifting world is whether high or low frequency lifting (e.g. a full body or upper/lower split in which you work every muscle, say, 2 or 3 times per week vs. a body part split in which you work each muscle group, say, once per week) is actually superior for the development of strength and hypertrophy.

Another study from the Schoenfeld lab addressed this question by having two groups of trained lifters participate in two different training regimens. One program consisted of a body part split where each muscle group was trained once per week overall, and the other program consisted of training the full body each day such that the total number of sets completed for each muscle group in a week’s time was the same for the two groups. While many of the results were not statistically significant, the results showed that the average increases in both muscle size and 1RM strength on the bench press and back squat were higher for every measurement in the full body, high frequency group when compared to the low frequency, body part split group. Now, although the total number of sets was the same, the full body group did end up completing slightly more volume (not a statistically significant amount) than the body part split group , which may not be perfect as far as the study is concerned, but it actually potentially highlights another benefit of higher frequency training.

Let’s say you are going to do 9 sets of squats for a given week. It’s not too hard to imagine that the average quality of each set of squats (in terms of form, mental attitude, etc.) would be better if you just did 3 sets of squats on 3 separate days instead of grinding through all 9 sets of squats at once, right?

It’s probably coming through in my writing here that I am a fan of higher frequency training. Typically, I do train most of my movement patterns two or three times per week (although deadlifts are usually kept down to once a week), and yes, it’s looking like the literature supports the idea that higher frequency training has some benefits over lower frequency training, but I am not going to deny the fact that some people do make great progress while training a movement or a muscle group just once per week. Granted, these are often very advanced lifters who have tremendously high work capacities and the ability to push their bodies a lot harder than the average person would be able to. In these cases, they may train so hard that they really do need a whole week off (or even more) before they are ready to go again.

For most people, though, training with higher frequency will probably yield better results in terms of hypertrophy, strength, and skill development with the trained movements.

Prilepins chart prilepin's table

Set/Rep Schemes – This is simply the template of how many sets of how many reps you will do for each movement in a training session (e.g. 5 sets of 5, or 3 sets of 10). This variable coupled with (or multiplied by) training intensity determine total training volume. As discussed above, total training volume and training intensity are two of the most influential determinants of the nature of the adaptations (hypertrophy and/or strength) that a training program will elicit, yet most of the time, it seems that lifters lay out their training plan without considering either of the former variables, instead basing everything solely on a specific set/rep scheme they feel is appropriate for their goals.

I’m not saying this is the worst thing in the world. Someone who wants to get stronger and decides to use the time tested 5×5 (5 sets of 5 reps) approach is still moving in a good direction. A more thorough strategy, though, would be to lay out a plan focusing first on the total training volume and training intensity that is most logical for working towards the lifter’s goals. The lifter can then determine a realistic number of reps that are doable per set at the desired intensity (Prilepin’s Chart (above) can be a great reference for this purpose), and from there, the number of sets falls into place based on the target training volume. Of course, there is certainly wiggle room in all of these variables. For example, you can plan within intensity ranges (e.g. 70-75% of 1RM) and rep ranges (e.g. 6-8 reps) to leave room for the variations in strength and energy levels that lifters will inevitably feel from time to time.

As for the time-honored advice that lifters should stick to lower rep ranges for strength development and higher rep ranges for hypertrophy, now that we’ve discussed the balance between training volume and training intensity and the effect of both of these variables on the body’s adaptation to training, you can see that this rule of thumb is really just the realization of how much volume our bodies can handle at a given intensity. In other words, it really comes down to intensity. It’s not that something about doing sets of 3-6 reps intrinsically makes us stronger so much as the fact that the weight that we need to move to make us stronger is a weight that we can probably only move for 3-6 reps at a time. If I could squat 500 pounds for 15 reps, you better believe that doing that would probably make me stronger than doing 500 pounds for 3-6 reps. Volume and intensity are key!

The take-home message is this: planning based solely on set/rep schemes is not necessarily a bad thing (especially for beginners), but once you get further along in your training, you will likely need to start paying heed to (and adjusting accordingly) your total training volume and training intensity to continue optimizing the pursuit of your goals, whatever they may be.

all aboard the gain train

Rep Speed/Execution – While there are many aspects of the execution of a single repetition (rep) of a movement that we could consider, I’m going to simply break this down into how quickly we are moving the weight during the eccentric (lowering of the weight/lengthening of the primary movers; often called the “negative” portion of the movement) and concentric (raising of the weight/shortening of the primary movers) portions of a lift.

A commonly recommended technique for inducing muscle growth is to practice slow (up to several seconds long), controlled eccentrics, or negatives, on each rep. I think that this idea has originated from a combination of knowledge tidbits. For one, we are typically able to exert more force in the eccentric phase of a lift than in the concentric phase (as witnessed by anyone that has seen someone lower a weight to their chest or into the hole only to get stapled when they try to lift it). Additionally, these recommendations often times make reference to increasing time under tension and the finding that muscles seem to undergo more damage during eccentric lengthening under load than they do during the concentric shortening phase (the hypothesis here being that muscle damage is a positive indicator for adaptive muscle hypertrophy). While it all sounds well and good, it doesn’t all seem to hold up to what has been observed in the literature.

For starters, a review/meta-analysis by (once again) Dr. Schoenfeld showed no significant difference in hypertrophy outcomes for repetition durations lasting from 0.5 – 8 seconds when analyzing the collective data from 8 studies that looked at the effects of different repetition speeds.

There does seem to be evidence that the eccentric phase of a lift is superior to the concentric phase for inducing hypertrophy in studies such as this one. However, even these findings do not support the idea of a slow eccentric being particularly beneficial for muscle growth. To elaborate, out of the four groups (fast concentric-only, slow concentric-only, fast eccentric-only, and slow eccentric-only) in this study, both eccentric-only training groups experienced greater muscle growth than the concentric-only training groups (looking good…).

However, the greatest increases in muscle size were observed in the fast eccentric-only group instead of the slow eccentric-only group, which throws a bit of a damper on the idea of using slow eccentrics. Of course, it’s also worth noting that the exercises in this experiment consisted of only an eccentric or concentric phase, which makes it harder to directly translate the results to the execution of normal reps that consist of both phases for most movements.

And sure, there are some studies like this one that show that out of two groups performing the same number of sets and reps, the group that performed their repetitions with 3 second eccentrics and 3 second concentrics experienced a larger increase in muscle size than the group that did their repetitions with 1 second eccentrics and 1 second concentrics. At first, this sounds great, but it starts to fall apart when you look at one little detail: both groups were doing the same number of sets and reps at the same intensity!

It’s not really too surprising that the slow group would experience more growth when volume was held equal but the slow group experienced drastically more time under tension (3 times the amount, to be exact). This was intended as a manner of controlling the experiment to look at only the effect of repetition speed alone, but the problem here is that this logic doesn’t really hold up to how this situation would actually play out in training, where a lifter could feasibly just do more repetitions (more total volume) before fatigue set in for them than the slow repetition group would be able to complete. I have a feeling that this would either balance the outcome on hypertrophy between the two methods or tip the scales towards the “normal” repetition speed group.

In short, while it’s possible that there is more to the picture or that I’ve missed a crucial study in my search, it just doesn’t seem like the idea of performing deliberately slow reps has much merit for improving the hypertrophic response to training (with the potential exception being when subjects do the same total volume with either fast or slow reps, but again, this could just be a result of increasing time under tension while holding everything else equal). That being said, you should definitely still strive to control the weight smoothly through the eccentric phase! Just don’t worry about moving slower than you need to to maintain control.

And before I switch over to talking about a couple of rep execution techniques, I will point out that doing heavy, overloaded eccentrics does seem to be a pretty effective way to build strength, but these are kind of a special exception, as you need to load more weight onto the bar than you can actually lift to put these into practice. If you are planning on the lifting the weight back up, it’s probably going to be in your best interest to move under control, but quickly in both the eccentric and concentric phases.

One rep execution technique that I will recommend for the development of strength and starting power is the pause rep. Pause reps are—as the name suggests—reps in which you incorporate a pause at some point in the movement. The pause can be initiated anywhere in the movement, really (on the way down, at the bottom, on the way up), and held for a varying amount of time. For most lifters, I would recommend pause durations somewhere in the 1-3 second range; any longer, and it gets pretty hard to complete an appreciable amount of work. Depending on the movement being paused (squats, bench press, etc.) I am normally a fan of pausing either at the bottom of the movement or partway through the concentric phase.

There are a few ideas behind pause reps. A lot of people like to pause at the bottom of a movement both to get more “comfortable” with being in that position and to practice moving the weight out of the hole without the bounce that might normally be there. When implementing pauses during the concentric, you are shedding all of the momentum from the bar and putting yourself in a situation where you need to generate more force than you otherwise would have had to in that position to get the bar moving again. This is one way to work on “sticking points” in a movement. As far as I know, this is a technique that hasn’t really been explored in the literature, but there are a lot of strong, intelligent people using pause reps with good success.

Lastly, before this turns into a full manifesto, I will just mention that there are several techniques such as drop sets, super sets, cluster sets, rest-pause training, etc. often referred to collectively as “intensity techniques” (not to be confused with the training intensity that measures loads relative to 1RM). For the most part, these methods enable lifters to extend the duration of their sets (more time under tension) and generate more metabolic stress than they normally would be able to just doing a single, conventional set. In short, they can certainly work for improving hypertrophy, but I’m not sure that there is any evidence that doing, say, a drop set for your last set of dumbbell curls is superior to simply doing an additional conventional set after taking your normal amount of rest (there are reasons to believe it could be, but this will have to be the topic of another post!)

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Training Density – Simply put, this is how much work you are doing in a given amount of time (this is actually your average power output by definition). For instance, doing 5 sets of 5 on the squat with 300 lbs in, say, 15 minutes would constitute a higher training density than doing that same 5 sets of 5 with 300 lbs in 25 minutes. Generally, training density will mostly boil down to how long you allot yourself for resting between sets or bouts of exercise. Why does this matter? Well, increasing training density is one way to improve your overall conditioning and work capacity, but this will likely come at a trade-off in intensity (at least in the short term).

A 2009 review of several studies looked at the effect of rest time between sets and found a few trends in the literature. For one thing, it is pretty clear that taking plenty of time (e.g. 3-5 minutes) between sets increases performance on subsequent sets for most people, which is important when training for strength with heavier loads. Unsurprisingly, the literature indicated that the opposite approach (short rest periods) are beneficial for improving muscle endurance. When it comes to training for muscle hypertrophy, it gets slightly more murky.

This review was quick to point out that several studies found that shorter rest durations between sets led to greater transient increases in growth hormone, but several of these studies did not see significant differences in muscle hypertrophy for different inter-set rest durations. It is worth noting, however, that this could be in part because in several of these studies, short and long rest duration groups were not volume-equated (those who had shorter rest periods tended to complete less volume due to fatigue), so there may be more to the story.

Just so, another review by Dr. Schoenfeld looked at ample evidence suggesting that there are several pathways by which metabolic stressors (conditions such as elevated concentrations of energy production metabolites like hydrogen ions and lactate that are typically induced by high rep resistance training, especially with shorter rest periods between sets) seem to induce growth in the absence of high levels of mechanical stress. This isn’t so surprising, given the success that bodybuilders have seen for decades with using methods like drop sets, super sets, and, more recently, blood flow restriction training (a pretty neat technique that I will discuss more some other time).

To sum it all up, increasing training density (doing more work in less time) is a great way to improve your overall conditioning and stimulate hypertrophy, but it will come at the expense of performance (i.e. all other things equal, with shorter rest durations between sets, you will not be able to use as much weight for as many reps on subsequent sets as you probably would be able to with longer rest durations between sets).

Let’s Talk Specifics

How does all this talk of training variables relate back to specificity? Well, as I mentioned here and there throughout the discussion above, each one of the six variables I covered can be manipulated to promote specific adaptations (for our purposes, we’re mostly talking about hypertrophy and the facets of strength here). Getting back to our hypothetical powerlifter trying to work on squat strength, we can see that there are specific combinations of these variables that would push his/her training from general to specific.

On the highly specific side of the spectrum, we would have very high training intensity, which would necessitate lower volume, lower reps per set, and lower training density. But, as discussed above, sticking only to these parameters all of the time might leave gaps in the lifters overall development. So, to work on improving conditioning, work capacity, and muscular size, the lifter might be inclined to at some point push towards the general side of the spectrum, increasing volume, reps per set, and training density, which would necessitate a decrease in training intensity.

Keep in mind that the level of specificity for whatever you are doing is totally dependent on your goals! For a bodybuilder looking to maximize hypertrophy, doing low volume, super high intensity training (e.g. 3-5 sets of 1-2 reps) might constitute more general, off season training that would be practiced to increase the amount of weight they can handle once they move into their more specific, higher volume training.

Next Time…

To recap, we’ve covered several ways we can adjust our level of specificity to gear our training towards supporting different facets of our end goal.

The next question is how do we mold all of this together into a coherent, effective plan. This leads us to the concept of periodization, but for that, my  friends, you’ll have to tune in next time.

As always, thanks for reading! If you are enjoying the content, please sign up for the newsletter, follow me through the social media links below, share the site with your buddies, and leave some love in the comments below. Be my friend (please)!

 

References

  1. Krieger, J.W., Single vs. multiple sets of resistance exercise for muscle hypertrophy: a meta-analysis. The Journal of Strength & Conditioning Research, 2010. 24(4): p. 1150-1159.
  2. Marshall, P., M. McEwen, and D. Robbins, Strength and neuromuscular adaptation following one, four, and eight sets of high intensity resistance exercise in trained males. European journal of applied physiology, 2011. 111(12): p. 3007-3016.
  3. Schoenfeld, B.J., et al., Effects of different volume-equated resistance training loading strategies on muscular adaptations in well-trained men. The Journal of Strength & Conditioning Research, 2014. 28(10): p. 2909-2918.
  4. Schoenfeld, B.J., et al., Influence of Resistance Training Frequency on Muscular Adaptations in Well-Trained Men. Journal of strength and conditioning research/National Strength & Conditioning Association, 2015.
  5. Schoenfeld, B.J., D.I. Ogborn, and J.W. Krieger, Effect of Repetition Duration During Resistance Training on Muscle Hypertrophy: A Systematic Review and Meta-Analysis. Sports Medicine, 2015. 45(4): p. 577-585.
  6. Farthing, J.P. and P.D. Chilibeck, The effects of eccentric and concentric training at different velocities on muscle hypertrophy. European journal of applied physiology, 2003. 89(6): p. 578-586.
  7. Watanabe, Y., et al., Increased muscle size and strength from slow-movement, low-intensity resistance exercise and tonic force generation. J Aging Phys Act, 2013. 21(1): p. 71-84.
  8. de Salles, B.F., et al., Rest interval between sets in strength training. Sports Medicine, 2009. 39(9): p. 765-777.
  9. Schoenfeld, B.J., Potential mechanisms for a role of metabolic stress in hypertrophic adaptations to resistance training. Sports medicine, 2013. 43(3): p. 179-194.

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