Showing posts with label muscle. Show all posts
Showing posts with label muscle. Show all posts
Monday, May 3, 2010
Occlusion Training: Tightening up everything we don't know about Hypertrophy
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If we asked someone "what should i do to build muscle" probably not a lot of people would say "cut off the blood flow to a working limb." Turns out though, that this latter kind of work - called occlusion training, or blood flow restriction (BFR) - has proven a powerful technique for inducing hypertrophy at very low loads (10-30% of a 1RM). While it's mainly been explored as a rehab technique to help accelerate recovery, some researchers have been looking at it as an approach in regular training. What, then, are the pro's and con's of this technique for training? And what are we learning about the mystery that is hypertrophy from studying the phenomena of occlusion for hypertrohhy strength?
These questions are addressed in an excellent review of occlusion research from 2008 called " Ischemic strength training: a low-load alternative to heavy resistance exercise?"
Two of the highlights of the paper (at least for me) -the review of hypertrophy models such as they are and a possible rationale for the Pump in bodybuilding circles.
Overview on the (un)Known of Muscle Building
The authors go through an amazing job of investigating the known models of hypertrophy - and all that we dont know about it - to see where occlusion training may fit in with existing models. Heck, in order to understand what role occlusion plays, we need to have some sense of the depth and breadth of the puddle it's playing in.
Unaccustomed as i am to being brief, i'm actually not going to go through these models in detail here. Suffice it to say though that what we have often thought of as the biggie thing to boost in order to super charge hypertrophy may not hold. The authors do a lovely job of showing for instance that heh, post occlusion training, yes Growth Hormone (GH) is up and IGF-1 is up, but according to all this other research, we really don't know if the presence of these hormone levels is really what's upping protein synthesis at all.
Not just hormones, the reviewers look at other factors too - like mechano checmical. THat means that maybe the calcium involved in the actin/myosin bridge that enables contractions is a key to what's really important for hypertrophy - but so far there aren't studies looking at these responses in occlusion, so we have no comparison.
This review is great for myth busting. In other words, its review of what we can actually point to and say "that's what casues muscle growth" shows us what we know is so small, it's really exciting. Why is being able to say "but we don't know if that's what's doing it" exciting? One, it means we're starting to know what's going on in more detail to be able to say we don't know and two, it means in any discussion about somebody saying this is WHY this works (like why the pump "works") we can be pretty confident in knowing they maybe shouldn't be so confident.
It may seem a fine point, but work like this also lets us continue to say that "if you do this protocol, you'll get big" - assuming it's been tested on lots of athletes of various types. What we cannot say with the same confidence is WHY if we follow that protocol we're getting big.
I recommend the full first half of the article just for this review of the state of the art (as of 2008) on hypertrophy.
SO where does this get us then with occlusion and hypertrophy?
First a few words about occlusion training - what is it?
Occlusion training goes by a bunch of names: kaatsu training, occlusion, Blood Flow Restriction (BFR), ishemic training. Occlusion generally means to obstruct or block or even hide something (from view). In the case of muscle work, the blood flow is obstructed, usually by a tournequette of some kind. Ischemia is sort of the technical term for blood flow restriction - to the heart or other body tissue -as a result of some type of block (or occlusion).
Protocols - often seem to involve tournequetting the working limb, then using loads of 10-30% of a 1RM, usually lots of reps, very low rest, until fatigue hits. The results in strength gains are similar to working sets with 80% 1RMs.
The main benefit has been seen in rehab, getting a person who's too weak to work at heavy levels, back on their feet again. There's even been consideration of the use of this kind of training for astraunauts who, following Woolfs' and Davis's law do tend to lose it from not using it - their muscle that is.
So, we can start to see with results like this, it would be interesting to understand how low loads with a cuff can cause strength gains equivalent to 80% of a 1RM
Is It Safe?
One of the biggie first questions people have about occlusion is (well, what was yours>) - is - is it safe? The authors respond that by saying they looked at 13 studies with thousands of trials - and even in the one where the forearm was completely occluded for 20mins, there were no measurable ill effects.
Most sessions last only 5-10 mins, and are not full, but partial occlusion.
Likewise, i was reading a 2010 study that wanted to see if thrombosis symptoms would occur in healthy participants - another concern about occlusion - and nothing close to that effect was measured. So from these typical kinds of fears, no such effects it seems have been measured.
The one side effect "acute muscle pain" - i think this means similar to the burn sensation some folks get when going too far in a set. That's common with the "to fatigue" type training used in occlusion. DOMS is also common in the first few bouts. The authors suggest that with these cautions in mind "training combined with ischemia clearly requires a high degree of motivation from the trainee, especially if performed with a high level of effort."
Will that be Wide or Narrow?
The consensus is it seems that wide cuffs have the advantage: lower pressures can be used with wider cuffs. Likewise there are fewer shear force issues with wider cuff and one can stay away from complete occlusion with more control.
Last year i looked at a study that just tied up the lower limbs with wide wraps. Important to note that the cuffs these folks are describing in the research reviews can have the pressure adjusted with the cuff to exact mmHg, similar to a blood pressure cuff.
I make no recommendations about whether it's better to use a proper occlusion cuff or just wrap up a limb; i only note that the places in Japan that have the most experience with this approach use Katsu cuffs - cuffs that enable control of pressure.
Is a Tournequette Even Necessary?
This is my favorite part of the paper because i think there's a link between what is described here, and what is discussed with the Pump (b2d overview here). See what you think.
First the authors point out that studies show the effect of an occlusion cuff is erased once loads get up to 40-60% load. What's interesting is that work using research's favorite - the leg extension - showed that even without a cuff, loads as low as 20% could induce "ischemic pain" - like that's a good thing.
The authors hypothesize that there are ways to get a low load ischemic effect without a cuff by doing the following: partials
So this is where my Pump query comes in: the Pump - if one is not overtraining and under nourished - is easy to achieve by using lots of reps with light loads, until one's arms or related feel like they're so full of blood they can't move. Sounds like kaatsu work.
Now there's been an ongoing debate about whether or not the Pump really leads to hypertrophy. Some of the vigerous come backs are "i never train for the pump and i still get big" - while true not really a defence. And actually, what hasn't been directly tested it seems is post ishemia self-induced, does hypertrophy occur? A lot of body builders will say yes.
What i'm intrigued by is that there seems to be a lot of circumstantial evidence to say that ishemia induced with low loads develops hypertrophy - but if anyone tries to say "and here's why that is" - and they start talking about NO supplements and flushing and who knows what all - you can pretty confidently say, well, based on what research?
In other words, there's a relationship it looks like, but what the actual mechanism is, we don't entirely know. Mybe it's fatiguing out type one and bringing on type II, maybe its IGF-1 goes up and myostatin goes down. Maybe it's mTOR levels. They're all in the soup. But what's cause and what's conincidence - ain't clear. But i sure as heck ain't gonna say the pump is a myth - just the explanations for it so far are pretty mythical.
To Cuff or Not to Cuff
One might think that just going for this kind of non-cuff'd based ischemia (blood pooling; can't flow back) is better than cuff based. Here's what the authors think:
What about the Dose?
To summarise a great long section of this paper, the results are not in for normal training about what the optimal frequence, volume, intensity is for optimal hypertrophic effect using occlusion.
The authors make a great note that not all ischemic training results in strength gains. For some reason, cycling isn't great for occlusion and strength development. On the other hand walk training is one of the big successes of occlusion work, and of course stength training - the short bursts of activity - is where the biggest benefit seems to be. Whether therefore the ratio between ischemia and reperfusion is key here, we just don't know but it seems to be a factor.
Will it Blend
So if we're not rehabbing, and with all the unknowns about dose, is it appropriate to put occlusion training into the mix of a regular strength program with "heavy" resistance.
I dunno.
The authors focus on work that's looked at two great benefits of heavy resistance training: bone mineral density and tendon stiffness.
In both cases lighter load work has been shown to have less of an effect on these factors. So - for ones bones, heavy resistance is a bonus - but then, so is stop and start action. For tendons, however, it seems that volume is also a key factor in enhancing stiffness (MTC descibed here - doesn't mean anything about flexibility, but about load, really)
In other words, while occlusion may not bring on the benefits of heavy resistance, there are other ways than heavy work to enhance these benefits so playing with ischemia may be useful for strength development.
High Volume towards Ischemia? Again, to take another page from bodybuilding and powerlifting practice, mechanisms to increase volume without killing form or inducing failure can be awesome. 
Trainer par excellance Roland Fisher introduced me to the timed sets of Huge in a Hurry
's Chad Waterbury. Very simple: get a weight at the end of a session where you can do 20 reps, and as soon as the fast tempo drops to complete the set, drop the weight, go for another 20. By using time as the marker, there's no way to get to fatigue and form failure. One heck of a pump, too. Thus, one has done their heavy work, and uses the occlusion level sets for a finisher. I love it. Your mileage may vary. See what you find.
Wrap UP - sans wraps even
And speaking of finisher, the authors wrap up with the following. The first sentence for me is key:
Meanwhile, if you wish to try occlusion training yourself, there's only about 4 uni's in the US using it; most work is in Japan. Here's an intereting PDF that talks about a specific Kaatsu cuff system, too.
The point is, i guess, that as this article started, just when we think we know something who'd a thought that strength can be aided by counter-intuitive actions like restricting blood supply? where does that map to evolution?
If nothing else, occlusion work shows us that we are complex systems with more than one path to create an effect.
Related Resources
Citations:
If we asked someone "what should i do to build muscle" probably not a lot of people would say "cut off the blood flow to a working limb." Turns out though, that this latter kind of work - called occlusion training, or blood flow restriction (BFR) - has proven a powerful technique for inducing hypertrophy at very low loads (10-30% of a 1RM). While it's mainly been explored as a rehab technique to help accelerate recovery, some researchers have been looking at it as an approach in regular training. What, then, are the pro's and con's of this technique for training? And what are we learning about the mystery that is hypertrophy from studying the phenomena of occlusion for hypertrohhy strength?These questions are addressed in an excellent review of occlusion research from 2008 called " Ischemic strength training: a low-load alternative to heavy resistance exercise?"
Two of the highlights of the paper (at least for me) -the review of hypertrophy models such as they are and a possible rationale for the Pump in bodybuilding circles.
Overview on the (un)Known of Muscle Building
The authors go through an amazing job of investigating the known models of hypertrophy - and all that we dont know about it - to see where occlusion training may fit in with existing models. Heck, in order to understand what role occlusion plays, we need to have some sense of the depth and breadth of the puddle it's playing in.
Unaccustomed as i am to being brief, i'm actually not going to go through these models in detail here. Suffice it to say though that what we have often thought of as the biggie thing to boost in order to super charge hypertrophy may not hold. The authors do a lovely job of showing for instance that heh, post occlusion training, yes Growth Hormone (GH) is up and IGF-1 is up, but according to all this other research, we really don't know if the presence of these hormone levels is really what's upping protein synthesis at all. Not just hormones, the reviewers look at other factors too - like mechano checmical. THat means that maybe the calcium involved in the actin/myosin bridge that enables contractions is a key to what's really important for hypertrophy - but so far there aren't studies looking at these responses in occlusion, so we have no comparison.
This review is great for myth busting. In other words, its review of what we can actually point to and say "that's what casues muscle growth" shows us what we know is so small, it's really exciting. Why is being able to say "but we don't know if that's what's doing it" exciting? One, it means we're starting to know what's going on in more detail to be able to say we don't know and two, it means in any discussion about somebody saying this is WHY this works (like why the pump "works") we can be pretty confident in knowing they maybe shouldn't be so confident.
It may seem a fine point, but work like this also lets us continue to say that "if you do this protocol, you'll get big" - assuming it's been tested on lots of athletes of various types. What we cannot say with the same confidence is WHY if we follow that protocol we're getting big.
I recommend the full first half of the article just for this review of the state of the art (as of 2008) on hypertrophy.
SO where does this get us then with occlusion and hypertrophy?
First a few words about occlusion training - what is it?
Occlusion training goes by a bunch of names: kaatsu training, occlusion, Blood Flow Restriction (BFR), ishemic training. Occlusion generally means to obstruct or block or even hide something (from view). In the case of muscle work, the blood flow is obstructed, usually by a tournequette of some kind. Ischemia is sort of the technical term for blood flow restriction - to the heart or other body tissue -as a result of some type of block (or occlusion).
Protocols - often seem to involve tournequetting the working limb, then using loads of 10-30% of a 1RM, usually lots of reps, very low rest, until fatigue hits. The results in strength gains are similar to working sets with 80% 1RMs.
The main benefit has been seen in rehab, getting a person who's too weak to work at heavy levels, back on their feet again. There's even been consideration of the use of this kind of training for astraunauts who, following Woolfs' and Davis's law do tend to lose it from not using it - their muscle that is.
So, we can start to see with results like this, it would be interesting to understand how low loads with a cuff can cause strength gains equivalent to 80% of a 1RM
Is It Safe?
One of the biggie first questions people have about occlusion is (well, what was yours>) - is - is it safe? The authors respond that by saying they looked at 13 studies with thousands of trials - and even in the one where the forearm was completely occluded for 20mins, there were no measurable ill effects.
Most sessions last only 5-10 mins, and are not full, but partial occlusion.
Likewise, i was reading a 2010 study that wanted to see if thrombosis symptoms would occur in healthy participants - another concern about occlusion - and nothing close to that effect was measured. So from these typical kinds of fears, no such effects it seems have been measured.
The one side effect "acute muscle pain" - i think this means similar to the burn sensation some folks get when going too far in a set. That's common with the "to fatigue" type training used in occlusion. DOMS is also common in the first few bouts. The authors suggest that with these cautions in mind "training combined with ischemia clearly requires a high degree of motivation from the trainee, especially if performed with a high level of effort."
Will that be Wide or Narrow?
The consensus is it seems that wide cuffs have the advantage: lower pressures can be used with wider cuffs. Likewise there are fewer shear force issues with wider cuff and one can stay away from complete occlusion with more control.Last year i looked at a study that just tied up the lower limbs with wide wraps. Important to note that the cuffs these folks are describing in the research reviews can have the pressure adjusted with the cuff to exact mmHg, similar to a blood pressure cuff.
I make no recommendations about whether it's better to use a proper occlusion cuff or just wrap up a limb; i only note that the places in Japan that have the most experience with this approach use Katsu cuffs - cuffs that enable control of pressure.
Is a Tournequette Even Necessary?
This is my favorite part of the paper because i think there's a link between what is described here, and what is discussed with the Pump (b2d overview here). See what you think.
First the authors point out that studies show the effect of an occlusion cuff is erased once loads get up to 40-60% load. What's interesting is that work using research's favorite - the leg extension - showed that even without a cuff, loads as low as 20% could induce "ischemic pain" - like that's a good thing.
The authors hypothesize that there are ways to get a low load ischemic effect without a cuff by doing the following: partials
Other quadriceps exercises can also be modified to achieve intramuscular restriction of blood flow. During closed kinetic chain exercises such as the squat and the leg press, the force demands of the movement dictate that the electrical activity of the quadriceps is high at flexed knee angles (90°–100°) and low near full-knee extension (Andersen et al., 2006). If the range of motion instead is limited to between ∼50° and 100° of flexion, the muscle activity remains fairly high throughout the movement and intramuscular occlusion is thus more likely to occur.The goal of going for ischemia with low loads is to get the benefit of heavier loads without having to use heavier loads that perhaps could not be taken to the given rep level.
So this is where my Pump query comes in: the Pump - if one is not overtraining and under nourished - is easy to achieve by using lots of reps with light loads, until one's arms or related feel like they're so full of blood they can't move. Sounds like kaatsu work.
Now there's been an ongoing debate about whether or not the Pump really leads to hypertrophy. Some of the vigerous come backs are "i never train for the pump and i still get big" - while true not really a defence. And actually, what hasn't been directly tested it seems is post ishemia self-induced, does hypertrophy occur? A lot of body builders will say yes. What i'm intrigued by is that there seems to be a lot of circumstantial evidence to say that ishemia induced with low loads develops hypertrophy - but if anyone tries to say "and here's why that is" - and they start talking about NO supplements and flushing and who knows what all - you can pretty confidently say, well, based on what research?
In other words, there's a relationship it looks like, but what the actual mechanism is, we don't entirely know. Mybe it's fatiguing out type one and bringing on type II, maybe its IGF-1 goes up and myostatin goes down. Maybe it's mTOR levels. They're all in the soup. But what's cause and what's conincidence - ain't clear. But i sure as heck ain't gonna say the pump is a myth - just the explanations for it so far are pretty mythical.
To Cuff or Not to Cuff
One might think that just going for this kind of non-cuff'd based ischemia (blood pooling; can't flow back) is better than cuff based. Here's what the authors think:
Intuitively, a training model which is based on the muscles own internal restriction of blood flow would have advantages both from a safety point of view and from a practical point of view. On the other hand, in certain muscle groups and in some individuals, it may be difficult to induce relative ischemia at low loads by exercise alone, due to factors such as insufficient intramuscular pressures developed during exercise. Furthermore, it is possible that there are differences between the muscle ischemia resulting from exercise alone and the ischemia induced with a tourniquet in combination with exercise (e.g., a greater build-up of metabolites in the cuff-occluded muscle), which in turn could lead to differences in the stimulation of hypertrophic pathways. Future studies should compare the effects of ischemic training with and without cuff occlusion at the same level of effort.Another great "we don't know" but a great question: is cuffing the same kind of physiological response as non-cuffing occlusion effect?
What about the Dose?
To summarise a great long section of this paper, the results are not in for normal training about what the optimal frequence, volume, intensity is for optimal hypertrophic effect using occlusion.
The authors make a great note that not all ischemic training results in strength gains. For some reason, cycling isn't great for occlusion and strength development. On the other hand walk training is one of the big successes of occlusion work, and of course stength training - the short bursts of activity - is where the biggest benefit seems to be. Whether therefore the ratio between ischemia and reperfusion is key here, we just don't know but it seems to be a factor.
Will it Blend
So if we're not rehabbing, and with all the unknowns about dose, is it appropriate to put occlusion training into the mix of a regular strength program with "heavy" resistance.
I dunno.
The authors focus on work that's looked at two great benefits of heavy resistance training: bone mineral density and tendon stiffness.
In both cases lighter load work has been shown to have less of an effect on these factors. So - for ones bones, heavy resistance is a bonus - but then, so is stop and start action. For tendons, however, it seems that volume is also a key factor in enhancing stiffness (MTC descibed here - doesn't mean anything about flexibility, but about load, really)
In other words, while occlusion may not bring on the benefits of heavy resistance, there are other ways than heavy work to enhance these benefits so playing with ischemia may be useful for strength development.
High Volume towards Ischemia? Again, to take another page from bodybuilding and powerlifting practice, mechanisms to increase volume without killing form or inducing failure can be awesome. Trainer par excellance Roland Fisher introduced me to the timed sets of Huge in a Hurry's Chad Waterbury. Very simple: get a weight at the end of a session where you can do 20 reps, and as soon as the fast tempo drops to complete the set, drop the weight, go for another 20. By using time as the marker, there's no way to get to fatigue and form failure. One heck of a pump, too. Thus, one has done their heavy work, and uses the occlusion level sets for a finisher. I love it. Your mileage may vary. See what you find.Wrap UP - sans wraps even
And speaking of finisher, the authors wrap up with the following. The first sentence for me is key:
By seeing an interesting strength effect from occlusion, that raises the question how is this working in terms of what we know about hypertrophy? Turns out that in asking what we know about hypertrophy, it's surprisingly still very little. Lots about what's happening in the soup with strength training, but not lots of clear A therefore B. Having occlusion in the mix gives us a great point of comparison to be able to say at least what's different with the following factors (or the same) when blood flow is restricted? what's going on that this is happening? That's cool.
The research on resistance exercise performed during ischemic conditions has so far provided important new insights into the physiology of strength training. In addition to being a possible alternative or complement to conventional high-load resistance training in certain situations, ischemic strength training may also have a place in sports training. Because relative ischemia can be induced at rather low loads in certain exercises even without tourniquets, external pressure may not always be necessary to achieve significant training effects. Also, any unique effects of cuff occlusion per se during exercise have yet to be determined because the increased training effects observed in the studies published to date may simply have been due to greater effort. With reference to training combined with cuff occlusion, current evidence suggests that this mode of exercise is relatively safe, but more research is needed especially regarding the potential adverse effects on soft tissues.
Meanwhile, if you wish to try occlusion training yourself, there's only about 4 uni's in the US using it; most work is in Japan. Here's an intereting PDF that talks about a specific Kaatsu cuff system, too. The point is, i guess, that as this article started, just when we think we know something who'd a thought that strength can be aided by counter-intuitive actions like restricting blood supply? where does that map to evolution?
If nothing else, occlusion work shows us that we are complex systems with more than one path to create an effect.
Related Resources
- Occlusion Training
- Get Huge or Die
- Protein Ingestion and Protein Sythesis
- Nutrient Timing for muscle building
- Creatine and Beta Alanine
- Does this stuff work?
- the Pump
Citations:
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Wernbom M, Augustsson J, & Raastad T (2008). Ischemic strength training: a low-load alternative to heavy resistance exercise? Scandinavian journal of medicine & science in sports, 18 (4), 401-16 PMID: 18466185
Madarame, H., Kurano, M., Takano, H., Iida, H., Sato, Y., Ohshima, H., Abe, T., Ishii, N., Morita, T., & Nakajima, T. (2010). Effects of low-intensity resistance exercise with blood flow restriction on coagulation system in healthy subjects Clinical Physiology and Functional Imaging, 30 (3), 210-213 DOI: 10.1111/j.1475-097X.2010.00927.x
Loenneke, J., & Pujol, T. (2009). The Use of Occlusion Training to Produce Muscle Hypertrophy Strength and Conditioning Journal, 31 (3), 77-84 DOI: 10.1519/SSC.0b013e3181a5a352
PDF
Saturday, April 24, 2010
Hypertrophy: More sets are Better than 1, from Day 1
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In strength training, research has looked at the question of "how many sets" to make a difference for strength - does it matter if we train with 1 set or multiple sets? Most research of late has put the strength question to bed: more sets = more strength. What is less known is the relationship of hypertrophy to strength development. Strength is about at least two things: neural adaptations - muscle firing patterns - to be able to lift stuff, and structural changes to be able to support these loads without tearing ourselves apart. The latter is generally known as hypertrophy. So an open research question has been: are the changes in real strength more about the neural side of the fence than the structural? According to work done to review a TON of studies that have ever bothered to measure hypertrophy along with strength, more seems to be better here, too. In other words, hypertrophy is playing a side-by-side roll in strength training. At least as far as we can tell from eligible studies. The juicy bits are highlighted.
This review is published in the April 2010 Journal of Srength and Conditioning Research. Here's the abstract:
The key bony bit of the result above is that some of us (i count myself in here) may need to change our thinking about the role of hypertrophy especially in the early phases of training with untrained participants. Now, that finding does not mean that noticeable mass gains are happening from day one, but it would mean that structural adaptations are happening way sooner in the process than has been pretty much taken as given for some time. For instance:
Related Links:
Citation:
In strength training, research has looked at the question of "how many sets" to make a difference for strength - does it matter if we train with 1 set or multiple sets? Most research of late has put the strength question to bed: more sets = more strength. What is less known is the relationship of hypertrophy to strength development. Strength is about at least two things: neural adaptations - muscle firing patterns - to be able to lift stuff, and structural changes to be able to support these loads without tearing ourselves apart. The latter is generally known as hypertrophy. So an open research question has been: are the changes in real strength more about the neural side of the fence than the structural? According to work done to review a TON of studies that have ever bothered to measure hypertrophy along with strength, more seems to be better here, too. In other words, hypertrophy is playing a side-by-side roll in strength training. At least as far as we can tell from eligible studies. The juicy bits are highlighted.This review is published in the April 2010 Journal of Srength and Conditioning Research. Here's the abstract:
Previous meta-analyses have compared the effects of single to multiple sets on strength, but analyses on muscle hypertrophy are lacking. The purpose of this study was to use multilevel meta-regression to compare the effects of single and multiple sets per exercise on muscle hypertrophy. The analysis comprised 55 effect sizes (ESs), nested within 19 treatment groups and 8 studies. Multiple sets were associated with a larger ES than a single set (difference = 0.10 +/- 0.04; confidence interval [CI]: 0.02, 0.19; p = 0.016). In a dose-response model, there was a trend for 2-3 sets per exercise to be associated with a greater ES than 1 set (difference = 0.09 +/- 0.05; CI: -0.02, 0.20; p = 0.09), and a trend for 4-6 sets per exercise to be associated with a greater ES than 1 set (difference = 0.20 +/- 0.11; CI: -0.04, 0.43; p = 0.096). Both of these trends were significant when considering permutation test p values (p < 0.01).
Mean hypertrophy effect size for single vs. multiple sets per exercise. Data are presented as means 6 SE. *Significant difference from 1 set per exercise (p <0.05).
There was no significant difference between 2-3 sets per exercise and 4-6 sets per exercise (difference = 0.10 +/- 0.10; CI: -0.09, 0.30; p = 0.29). There was a tendency for increasing ESs for an increasing number of sets (0.24 for 1 set, 0.34 for 2-3 sets, and 0.44 for 4-6 sets). Sensitivity analysis revealed no highly influential studies that affected the magnitude of the observed differences, but one study did slightly influence the level of significance and CI width. No evidence of publication bias was observed. In conclusion, multiple sets are associated with 40% greater hypertrophy-related ESs than 1 set, in both trained and untrained subjects.Correlation of Hypertrophy with Strength. To get into the detail a little further, after the results are presented of comparing the various studies' methods, muscles, participants and periods of study, the author states:
This is a nice finding: hypertrophy - structural changes in muscle - seems to go hand in hand with strength, and right from the start of training. This is interesting in no small part because changes in measurable muscle size seem to lag behind measurable differences in strength.In a previous meta-analysis on strength using an identical statistical model, a 46% greater ES was observed for multiple sets compared with single sets (23) (Figure 3). A 40% greater ES was observed in this study. This indicates that the greater strength gains observed with multiple sets are in part because of greater muscle hypertrophy.
It is known that mechanical loading stimulates protein synthesis in skeletal muscle (39), and increasing loads result in greater responses until a plateau is reached (24). It is likely that protein synthesis responds in a similar manner to the number of sets (i.e., an increasing response as the number of sets are increased, until a plateau is reached), although there is no research examining this. The results of this study support this hypothesis; there was a trend for an increasing ES for an increasing number of sets. The response appeared to start to level off around 4-6 sets, as the difference between 2-3 sets and 4-6 sets was smaller than the difference between 1 set and 2-3 sets (figure 4)
Dose-response effect of set volume on strength from Krieger (23). Note similarity to dose-response effect for hypertrophy in Figure 2. Data are presented as means ± SE. ES = effect size. *Significantly different from 1 set per exercise (p < 0.001).
It has been proposed that the majority of initial strength gains in untrained subjects are because of neural adaptations rather than hypertrophy (28). The results of this analysis suggest that some of the initial strength gains are because of hypertrophy. Given the insensitivity and variability of hypertrophy measurements, it is likely that hypertrophy occurs in untrained subjects but is difficult to detect. This is supported by research that shows increases in protein synthesis in response to resistance training in untrained subjects (24). Recent evidence also shows measurable hypertrophy after only 3 weeks of resistance exercise (38).
What the studies do not discriminate about is whether these hypertrophic adaptations are more myofibrial or sarcoplasmic. And that rather makes sense as the main consideration has been (1) strength and (2) simply whether or not hypertrophy is more or less corelevant with the development of neural adaptations that lead to strength.
Practical Application
Practical Application
A super attribute of the JSCR articles is their "practical application" section - what can someone do with these results. The first application Krieger suggests is to get behind the awareness that hypertrophy increases from day one from more sets. In other words the number of sets does make a difference whether a beginner or not. Cool. Move it move it:
The second point is that those multiple sets make a statistically significant difference in terms of the amount of hypertrophy. More is more (at least up to 4-6 sets) for strength and structural development.Multiple sets per exercise were associated with significantly greater changes in muscle size than a single set per exercise during a resistance exercise program. Specifically, hypertrophy-related ESs were 40% greater with multiple sets compared with single sets. This was true regardless of subject training status or training program duration.
So while 1 set is certainly not useless, it mayn't be optimal (where that means before we hit a plateau). What remains to be done, according to Krieger, is to figure out that optimal set range:There was a trend for an increasing hypertrophic response to an increasing number of sets. Thus, individuals interested in achieving maximal hypertrophy should do a minimum of 2-3 sets per exercise. It is possible that 4-6 sets could give an even greater response, but the small number of studies incorporating volumes of ≥4 sets limits the statistical power and the ability to form any definitive conclusions. If time is a limiting factor, then single sets can produce hypertrophy, but improvements may not be optimal.
More research is necessary to compare the effects of 2-3 sets per exercise to ≥4 sets. Future research should also focus on the effects of resistance training volume on protein synthesis and other cellular and molecular changes that may impact hypertrophy.
Practical Awareness
For beginners interested in doing more sets, excellent. What to watch out for: fatigue. Stay fresh. Might be a grand idea to make sure to get a program that waves the volume so that there's ample recovery. Without that recovery, growth in strength/hypertrophy does seem to get retarded pretty fast.
For more experienced trainees, from what i hear among the folks i work with is: want to get bigger? lift more. More sets. more reps. more more more. The question this article nicely raises is what's an optimal more? Will be interesting to see if, when and how this question is formally explored in the future.
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- b2d General Fitness Articles
Citation:
Krieger JW (2010). Single vs. multiple sets of resistance exercise for muscle hypertrophy: a meta-analysis. Journal of strength and conditioning research / National Strength & Conditioning Association, 24 (4), 1150-9 PMID: 20300012Tweet Follow @begin2dig
Saturday, September 26, 2009
"Lean Muscle "- muscle is lean - do you mean lean mass?
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Just a quicky about terminology. I've heard many folks referring to building "lean muscle" and burning fat. Even seemingly knowledgeable sites do this. Consider this wikianswer response about building "lean muscle" A review of Staley's muscle logic refers to building "lean muscle mass." Or just do a search for "lean muscle" and check how many sites come back with that
term in the title.
The thing is, muscle *is* lean in that (a) lean means wanting in fat and (b) muscle has very little fat in it. Pretty much ever. It's very particularly designed to be that way.
The "lean muscle" may come from conflating the desire for muscle gain and fat loss on the one hand and measuring "lean mass" relative to body fat % from body composition on the other.
Or maybe it's that gaining muscle is supposed to go with burning fat and hence getting lean. Not always true by the way: see "bulking."
Anyway, lean muscle may be a redundant term but it's pretty pervasive. So let's take these terms apart then:
Lean, in lean mass refers to the measurement of the body sans adipose tissue - the fat that's under the skin (and can be measured by calipers) as opposed to visceral fat, which is the stuff around our internal organs.
Body composition by the way is formally the meanure of fat, bone, muscle tissue. So a lean person - say a man below 10% body fat with a six pack starting to show - is "lean" - as in wanting in fat (that's another great word: to want, wanting - as in to lack). He may be more or less muscular at that bf% than another person who is say
bigger or smaller boned, so not everyone at a particular bf% looks the same to be sure.
Similarly someone can gain lean mass, or gain muscle, and not necessarily put much of a dent in lowering their body fat percentage (as seen recently with obese kids on exercise programs). In fact many folks will eat more to gain muscle mass, and pack on some more fat while doing so. This is partially why it's hard to gain muscle mass while reducing calories to get lean: the fuel to build the muscle mass (new tissue) isn't necessarily there (see discussion on hypertrophy here).
So, there's muscle, there's lean mass, and there's body fat. Muscle and bone is lean; fat is fat. Working to gain muscle doesn't necessitate getting lean(er), but eating at a caloric deficit may (scroll dow to see discussion on weight loss, nutrition, habits, change is pain, here for more).
Now, for most situations the above may be considered a nice distinction (nice is another cool word like want - means fussy or fastidious or jesuitical for that matter), but sometimes folks make the assumption that muscle gain means fat loss when thinking about "lean muscle gain" and since it doesn't, it may help to have this cleared up - help a person working on weight loss and fitness to have a better mental model of what's happening within us.
And so thar we go: muscle is lean already, to get lean is to drop fat, but building muscle is no guarantee of fat loss, though developed in the right circumstances, it can certainly help. Tweet Follow @begin2dig
term in the title.The thing is, muscle *is* lean in that (a) lean means wanting in fat and (b) muscle has very little fat in it. Pretty much ever. It's very particularly designed to be that way.
The "lean muscle" may come from conflating the desire for muscle gain and fat loss on the one hand and measuring "lean mass" relative to body fat % from body composition on the other.
Or maybe it's that gaining muscle is supposed to go with burning fat and hence getting lean. Not always true by the way: see "bulking."
Anyway, lean muscle may be a redundant term but it's pretty pervasive. So let's take these terms apart then:
Lean, in lean mass refers to the measurement of the body sans adipose tissue - the fat that's under the skin (and can be measured by calipers) as opposed to visceral fat, which is the stuff around our internal organs.
Body composition by the way is formally the meanure of fat, bone, muscle tissue. So a lean person - say a man below 10% body fat with a six pack starting to show - is "lean" - as in wanting in fat (that's another great word: to want, wanting - as in to lack). He may be more or less muscular at that bf% than another person who is say
bigger or smaller boned, so not everyone at a particular bf% looks the same to be sure.Similarly someone can gain lean mass, or gain muscle, and not necessarily put much of a dent in lowering their body fat percentage (as seen recently with obese kids on exercise programs). In fact many folks will eat more to gain muscle mass, and pack on some more fat while doing so. This is partially why it's hard to gain muscle mass while reducing calories to get lean: the fuel to build the muscle mass (new tissue) isn't necessarily there (see discussion on hypertrophy here).
So, there's muscle, there's lean mass, and there's body fat. Muscle and bone is lean; fat is fat. Working to gain muscle doesn't necessitate getting lean(er), but eating at a caloric deficit may (scroll dow to see discussion on weight loss, nutrition, habits, change is pain, here for more).
Now, for most situations the above may be considered a nice distinction (nice is another cool word like want - means fussy or fastidious or jesuitical for that matter), but sometimes folks make the assumption that muscle gain means fat loss when thinking about "lean muscle gain" and since it doesn't, it may help to have this cleared up - help a person working on weight loss and fitness to have a better mental model of what's happening within us.
And so thar we go: muscle is lean already, to get lean is to drop fat, but building muscle is no guarantee of fat loss, though developed in the right circumstances, it can certainly help. Tweet Follow @begin2dig
Sunday, May 10, 2009
Myth Busting: Women are afraid of "bulking up" in working out - not!
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After reading a variety of posts on forums asserting that women are afraid of bulking up, i've been running a survey this past week of gals who do workout in whatever form they define "workout" to see if actual women hold these views - or if this assertion is just one more urban legend.
(update 1, below)
so far there have been 28 respondents to the following 3 positions:
1. i adjust my workouts deliberately to avoid muscular "bulk"
2. i adjust my workouts at least some of the time deliberately to achieve some "bulk"
3. i don't think about "bulk" at all when i do my workouts
Responses
1. only 1 person
2. 11 gals
3. 16 gals
So, 40% picked that they DO go for bulk deliberately at least some of the time, while a whopping 57% (who also commented that they lift heavy) don't think about bulk one way or the other when they design their programs they "just want to get strong," or fast, and only 3% said they are concerned to make sure they won't induce bulk from their workouts.
That's a pretty significant inversion of the assumptions that have been expressed like some kind of truth about women's attitudes towards working out.
I'll update after another week if the numbers start to change, but i hope from this tiny sample at least some assumptions about "women" and their views of working out might get updated in folks' heads.
UPDATE 1:
response so far from a few of the gentlemen of good will who have seen this:
Update 2: (may 31, 09)
Since the results haven't changed for a week, here's the latest numbers on the the straw poll survey: of 52 respondents, 88% either don't care or from time to time deliberately do try to "bulk"
Fascinating again.
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(update 1, below)
so far there have been 28 respondents to the following 3 positions:
1. i adjust my workouts deliberately to avoid muscular "bulk"
2. i adjust my workouts at least some of the time deliberately to achieve some "bulk"
3. i don't think about "bulk" at all when i do my workouts
Responses
1. only 1 person
2. 11 gals
3. 16 gals
So, 40% picked that they DO go for bulk deliberately at least some of the time, while a whopping 57% (who also commented that they lift heavy) don't think about bulk one way or the other when they design their programs they "just want to get strong," or fast, and only 3% said they are concerned to make sure they won't induce bulk from their workouts.That's a pretty significant inversion of the assumptions that have been expressed like some kind of truth about women's attitudes towards working out.
I'll update after another week if the numbers start to change, but i hope from this tiny sample at least some assumptions about "women" and their views of working out might get updated in folks' heads.
UPDATE 1:
response so far from a few of the gentlemen of good will who have seen this:
- must be a special group of women i surveyed, like just uni athletes or "women who know better" or "non advanced women athletes" or not the women a fellow sees in the gym who aren't "working out to their potential."
- These fellers make general statements about "women" of some class/group/category despite citing resources - but a sort of implicit reference to "common knowledge" which seems to be more persuasive than the actual data presented here (and by their own female peers).
- They resonate with the other 97% of women who participated in the survey - they either don't care themselves about adding visible muscle or not, or are into getting some muscle mass.
- These women have not generalized to knowledge of other women or "women" as a general class beyond knowledge of themselves or peers with whom they've deliberately discussed the matter.
Update 2: (may 31, 09)
Since the results haven't changed for a week, here's the latest numbers on the the straw poll survey: of 52 respondents, 88% either don't care or from time to time deliberately do try to "bulk"
Fascinating again.
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