Intermittent Thoughts on Building Muscle: IGF-1 and its Splice Variants MGF, IGF-IEa & Co - Master Regulators or a Bunch of Cogs in the Wheel of Muscle Hypertrophy?

Image 1: With regard to IGF-1 and its splice-variants like MGF, there is probably 10x-100x more bro- than pro-scientific data out there - this does not help us, though, since you never know which of the bro-reports is bogus and which is not.

In view of the fact that we have not covered much ground with the last installment (we did build a pretty solid foundation, though ;-), I will try my very best to steer a middle course between presenting impressive amounts of facts and explaining the complex and in part not even completely elucidated physiological underpinnings of skeletal muscle hypertrophy, or, as the bros would say, getting big and buffed! A pros pros Bro, you will unquestionably have read on one of the myriads of bodybuilding-related bulletin boards how the injection of X amounts of IGF-1 right into the muscle made BigGuns, or whatever the poster's pseudonym may have been, grow "3 inches in 2 weeks"... ok, his profile picture looks impressive, but is that credible? Does IGF-1 really have such profound effects on muscle growth? And about what type of growth are we talking here? The myostatin-negative "ballooning up" of the muscle, which leaves you with overblown myogenic domains and dysfunctional muscles?

IGF-1: Insulin, growth hormone, or what?

To be able to answer these and related question we will first have to understand what exactly this "insulin-like growth factor 1" actually is. From a (bio-)chemical perspective it is nothing but a bond of 70 amino acids which are entangled into a specific peptide structure that is characteristic for somatomedin C, as IGF-1 is also called. Both the "growth" in IGF-1, as well as the "somato" in its old-fashioned appellation already suggest that what we are dealing with, here, is a "growth hormone related" polypeptide. And in fact, the synthesis of IFG-1, which, in the case of the systemically available fraction, takes place primarily in the liver, and is triggered by systemic growth hormone (somatotropin) levels.

Figure 1: Changes in systemic IGF-1 levels after 5-weeks on either a "normal" (=55:15:30 carbs:protein:fats) or a low carb "high protein" (=20:30:50) diet in 8 men with untreated type II diabetes (data adapted from Nuttal. 2006)

The "insulin" in its name, however, is pretty misleading... or I should say people mislead themselves, by not reading  the name correctly: It's not "insulin-growth factor", but "insulin-like growth factor" and the "like" refers to the structure of the molecule and does not imply that it is released in response to insulin spikes, as you may have read it on one of the aforementioned bulletin boards. If you do take a look at the growth hormone and IGF-1 levels of eight male subjects in a 2006 study on the metabolic of 5-weeks on what the scientists call a "high protein, low carbohydrate diet" (Nuttall. 2006), you will see that an increase in protein and fat from 15% to 30% and 30% to 50%, respectively elicited an 34% increase in serum IGF-1 levels over the treatment period, a finding that is corroborated by the recently published results of Matthew B. Cooke and his colleages from the Department of Health, Human Recreation and Performance at Baylor University.

Figure 2: Serum IGF-1 levels in response to whey vs. maltodextrin supplementation and subsequent lower body resistance training (data adapted from Cooke. 2011)

In their randomized double-blinded cross-over study, Cooke et al. had a group of 10 recreationally active men (2-3 non-resistance training exercise sessions per week) perform a lower body exercise program (leg presses and knee extensions, 4 sets, 8-10 reps at 80% of the individual 1RM) with either 10g of maltodextrose or 10g of whey 30 minutes before the exercise bout (Cooke. 2011). The results of the study (equal IGF-1 response regardless of whey or carbohydrate supplementation) imply that even in the short term, in healthy subjects and in conjunction with exercise the ingestion of carbohydrates is not superior to the provision of fast acting protein sources as a means to either increase or maintain systemic IGF-1 levels.

On a side note: The insulin-mediated induction of Akt, which subsequently triggers the phosphorylation of the mammalian target of rapamycin (mTOR) and thusly does its bit to elevate protein synthesis, has no direct relation to IGF-1, which - I cannot emphasize that enough - has a structure resemblance to insulin, nothing more, nothing less. And what's more, the insulin response in the aforementioned study by Cooke et al. was identical in the whey vs. maltodextrin arm of the study.

Systemic vs. local IGF-1 expression: A crucial distinction

If you have been following the daily research updates here at the SuppVersity over the last months, you may now be wondering why I am even caring about those growth hormones (after all you should, after reading the first paragraph, realize that IGF-1 is something like the active incarnation of somatotropin), when Stuart Phillips lab has quite conclusively shown that even the exercise induced elevation of testosterone does not correlate with subsequent increases in muscle protein synthesis. Certainly a good question, but nevertheless not difficult to answer:

1. The previous installments of the Hypertrophy 101 (Part 1, Part 2) should have made it quite clear that protein synthesis alone is not sufficient to grow. Without intra-muscular restructuring / reorganization and the recruitement of new myonuclei from satellite cells, you would sooner or later grow beyond the maximally allowed myonuclear domain sizes (assuming that by whatever means you block the healthy upregulation of mystatin that will prevent that) and end up as an over-muscled but completely dysfunctional wrack.
2. In a very recently published study, the results of which I have actually been holding back, because I thought I would get to them much earlier in this series, the very same Stuart Phillips whose studies are "responsible" (in fact it is the way they are discussed by the lay-press and abused by the supp-companies that is actually "responsible") for the current over-emphasis on acute increases in the protein synthetic response to exercise and/or supplements, reports that there actually was a statistically significant correlation between exercise induced growth hormone release and increases in mean type I fiber (p<0.06) and type II (p<0.04) cross-sectional area (CSA) in 56 healthy previously non-resistance trained healthy young men in response to a 12-week, 5-day per week resistance training regimen (West & Phillips. 2011).
3. While we have hitherto been talking about systemic IGF-1, it has become evident in the course of the last decade that the hepatic IGF-1 output, which is the main determinant of circulating IGF-1 levels, has little to no impact on the IGF-1 induced increases in skeletal muscle mass and remodeling of muscle tissue that has been previously studies in Petri dishes. In fact, recent research suggests that, just like the liver produces IGF-1 for "the whole body", muscles produce their own IGF-1, or I should say, their own IGFs-1, whenever they are challenged to grow and/or repair (Velloso. 2010), and that the decline of muscle mass with age is at least in parts attributable to a defect / reduction in the expression of local IGF-1 splice variants (for an explanation of what this is, see red box below).

If we now count 2. and 3. together the result is not 5. but rather that it is the growth hormone mediated, exercised-induced local expression of IGF-1 splice variants, which drives the repair and restructuring process that allows for continuous (healthy) muscle growth.

Did you know that the intra-muscular (=autocrine, meaning directly in the tissue where it is supposed to work) "construction process" of the mature 70 amino acid polypeptide IGF-1 gives rise to three different splice variants of insulin-like growth factor (note: the structure of IGF-1 gene does theoretically allow for 6 variants)? And though we are just beginning to understand the physiological roles of IGF-IEa, IGF-IEb and IGF-IEc, also known as MGF (mechano-growth factor), their distinctly timed expression in response to physical overload appears to constitute one of the major driving forces of myocellular hypertophy.

In order to fully understand the role "the" insulin-like growth factor 1 plays in the physiology of muscle growth, it is thusly important to realize that the common perception of IGF-1 as a systemic hormone is, at best, incomplete - I would even venture to say that it is totally flawed.

MGF?! Yeah, I have heard of that one!

Figure 3: Stained myocyte migration (top) and infiltration (bottom) essays for IGF-1 and MGF; more stains = greater effect (taken from Mills. 2007).

Of the three primary splice variants that are expressed in skeletal muscle, IGF-IEc, or MGF (Mechano-Growth Factor) has probably received the greatest attention - so much attention that even the aforementioned bros, will probably have grasped the notion that this is somewhat of a local isoform of IGF-1 which is expressed in response to exercise induced muscle damage and could potentially be the magic bullet to grow beyond what we have hitherto believed to be possible... and, guess what, in essence this appears to be correct.

In one of the earlier studies on the cellular effect of MGF, Yang et al. were able to show that MGF stops the IGF-1 mediated cell differentiation process (in practice this means that it stops the satellite cells from differentiating = specializing and becoming muscle cells) and increases their proliferation. Or put more simply: While in vitro exposition to IGF would suffice to build muscle, as long as there are enough progenitor cells (satellite cells) available, MGF is necessary to replenishes the satellite cell pool of which you have learned in the previous installments that it is necessary to a) repair damaged muscle tissue and b) increase the number of myonuclei in order to grow beyond the physiological growth limit that arises due to the muscle-type-specific upper limit to the myonuclear domain size (cf. previous installments).

Figure 4: Cell proliferation data in response to MGF treatment after blocking the IGF-I receptor.

As the data in figure 4 goes to show the effects of the complete polypeptide IGF-1 and its splice variant MGF appear to be mediated, at least partly via distinct receptors. And while recent research suggest that MGF also exerts similar effects on tendon (Olesen. 2006), brain (Dluzniewska. 2005) and nervous tissue (Aperghis. 2004), our primary concern here, is its pivotal role in muscle repair, which involves the activation of satellite cells, their proliferation (Yang. 2002) and migration (Mills. 2007).

A series of studies by Hammad et al., which was originally intended to investigate the effects of age on the expression of the different IGF splice variants, goes to show that the "muscle (re-)building effects" of MGF are not restricted to the test tube. In their 2002 study (Hamed. 2002), the researchers were able to show profound increases in the MGF expression in the quadriceps muscles of 8 healthy young men (age 29.5 ± 1.5 years, body mass 81.1 ± 2.4 kg, height 179.3 ± 1.8 cm) 2.5h after a single muscle-damaging leg-extension exercise (10 sets of 6 repetitions at 80% 1-RM, 2 min rest between sets):

Figure 5: MGF (ng mRNA / 10^8 µg RNA) and IGF-IEa ng mRNA / 10^5 µg RNA) expresion in quadriceps muscle of young subjects before and 2.5h after 10 sets of 6 repetitions at 80% 1-RM on a leg-extension machine with 2min rest between sets (data adapted from Hamed. 2002)

If you take a closer look at the data in figure, you will probably notice that there was one subject with an extreme MGF response, the scientists explain by a particularly high type-IIx fiber content of the quadriceps of this individual. If you remember the mouse studies and the analysis of the muscle composition of bodybuilders from the previous installments, you will be aware that the shift from type IIb to type IIx muscle fibers is one of the main characteristics of "getting real big". The extreme MGF response (>10x higher than the mean MGF expression across the other subjects) in this subject thusly suggests the increased growth capacity of type IIx muscle fibers is in part due to their ability to release MGF in response to strenuous exercise and thusly multiply / replenish their satellite cell pool to prepare for future growth.

Figure 6: MGF (ng mRNA / 10^8 µg RNA) and IGF-IEa ng mRNA / 10^5 µg RNA) expresion in quadriceps muscle of young subjects after eccentric HIIT exercise on cycle ergometer (data adapted from Hamed. 2008)

Interestingly, a 2008 follow up study (this time involving nine healthy young men aged 20–27 years, cf. Hamed. 2008) with a completely different training protocol that consisted of

60min of opposing the rotation of the pedals down to 60 r.p.m. Subjects performed the following program of six working intervals: six working intervals: 0–6min at 50%, 6–12min at 75%, 12–20min at 100%, 20–25min at 130%, 25–40min at 100% and 40–60min at 75% of the load  eliciting concentric VO2max

illicited surprisingly similar results (cf. figure 6). And in both cases, it appears to be the MGF splice variant not the IGF-IEa variety that drives the short term (hours to days) response to strenuous exercise.

HIIT and resistance training a dynamic duo for MGF expression

Assuming that you are following each and every post here at the SuppVersity (you know you should be ;-), this should remind you of a previous blogpost of mine (cf. "HIT Your Satellite Cells to Increase Your Gains!"), in which I explained that one of the many advantages of high intensity training (not even interval) over classic "cardio" training is that it can increase satellite cell proliferation. Now, with this installment of the Intermittent Thoughts you finally understand, why this is the case.

Image 2: This is not the kind of muscle damage you should be aiming for in the gym.

Now, while protein synthesis and increases in domain size are partly mediated via nutrition, the intra-muscular expression of the IGF-IE splice variants appears (at least based on the current research) to depend solely on exercise, or I should say the wear and tear that goes hand in hand with heavy exercise. In that it seems to be less important, whether you are "pumping away" or "cycling like maniac", as long as its "hard" - to put that into perspective, in the 2008 study by Hamed et al. the subjects underwent ~3600 eccentric muscle contractions in only 1 h, their creatine kinase (CK) levels (marker of muscle damage) increased by +183% and all subjects reported profound muscle soreness.

This controlled amount of muscle damage ties in nicely with the topic of next week's installment which will center around the the intricate relation of the inflammatory response to exercise, the expression of the well-known and less known inflammatory cytokines, TNF-alpha, IL-6 and IL-15 (sorry, Trevor, I have already gone overtime, so your question will have to wait till next week ;-) and the muscle (re-)building effects of IGF-1 and its intra-muscular children.

Sleep to Grow, Train to Sleep: How Strength and Endurance Training Effect Your Sleep Patterns & Exercise Performance and May Help or Hinder Fat Loss & Muscle Gains

Image 1: As a toddler you already knew - "Sleep is the most anabolic agent there is"; Sleep - Train - Eat, repeat! Remember that ;-)

If you like Dave Palumbo's Heavy Muscle Radio, you will probably have heard an advertisement that (a few other questionable statements aside) contains a real gem of wisdom: "Sleep is the most anabolic agent there is!" But how come? Well, if you remember the comments I made on the way your muscles grow by both, increasing mononuclear domain sizes (protein synthesis) and the accumulation of new myonuclei, you will probably also remember that, next to estrogen, nitric oxide and a handful of other factors, growth hormone, in general, and the IGF-1 (and MGF-1) that is locally released in response to its secretion, are the primary drivers of satellite cell driven muscle hypertrophy (and possibly hyperplasia)... now, guess when your body produces the lion share of growth hormone (and downstream IGF-1?) in a given day?

You got it, in those cosy (hopefully) ~8 hours you are snorkeling away in between your sheets (Cauter. 1998) - it is in these hours, that your GH levels spike at 600% of their daytime average and your cortisol levels plummet into the abyss. As studies show, this is yet not the only thing on which you are missing out if you do not get your share of quality sleep day in, day out: Even short-term (let alone chronic) sleep deprivation has been shown to significantly increase rates of perceived exertion in athletes and - and this may be even more detrimental - decrease insulin sensitivity and glucose tolerance (VanHelder. 1989). So that after nights and nights of low-quality or insufficient sleep, your secret weapon against tiredness, your pre-workout high-carb-get-me-going shake will no longer get you going in the gym, but rather out of the gym and right to your doctor to ask him for a script for some Metformin to get your blood sugar levels back to normal.

Assuming that I now got your full attention, I want to share the results of two very recent studies with you. One on the differential effect of strength and endurance training in the morning (10am) on sleep quality and duration in 15 healthy trained men (Roveda. 2011) and a second one on the beneficial effects even a single session of resistance training (at 60%RM) has on the sleep pattern of 22 65-85 year old men (Viana. 2011).

Always remember: Sleep is the most anabolic agent there is

One thing upfront: A reasonable amount of physical activity will - regardless of your age and fitness level - make it easier to fall asleep, lengthen the time you spent in bed actually sleeping and not tossing and turning, and contribute to an overall improvement in sleep quality.

Figure 1: Relative changes (compared to baseline) in assumed and actual sleep on day 1 and day 2 after a 10am strength (bench press 4x80RM + 10 min warm up)or endurance training (10min warm-up, 30min 80%VO2max, 10min cool-down) session in 15 healthy young men (data calculated based on Roveda. 2011).

As figure 1 goes to show there was a distinct effect of both strength and endurance training on the time spend in bed (assumed sleep) and the actual sleep time on the first day after the physical activity. In that, it is particularly noteworthy that the actual sleep time increased by +8% and +12.5% and thusly ~2% more than the time the subjects spent in bed. This increase in sleep quality is something we also see in the older subjects of the Viana study, whose REM latency, i.e. the time it took them to enter into the valuable rapid eye movement phase of their sleep, decreased by a whopping -48%, on days on which they had performed their 3 sets of 12 reps (60%RM) of chest presses, leg presses, vertical tractions, leg curls, biceps curls, abdominal crunches, arm extension, and lower back exercises.

Figure 2: Relative changes in sleep efficiency and sleep latency on day 1 and day 2 after a 10am strength or endurance training session in 15 healthy young men (data calculated based on Roveda. 2011).

Now, while we see a "rebound" effect (a decrease in sleep time) in the 2nd night after the morning exercise in the young subjects (comparative data were not collected in the Viana study), the increase in sleep efficiacy, i.e. the amount of time the young men spent in bed vs. the amount of time they actually sleep persisted (cf. figure 2)! And the sleep latency, i.e. the time it took the subjects to fall asleep was still significantly reduced on day 2 after the respective physical activities.

Although there probably is no doubt that physical activity may benefit sleep quality and sleep quality in turn may benefit not only the performance during the former, but also its effects on your metabolic health and body composition (cf. image 1), it is still a matter of constant debate how much, is too much - after all, both forms of overtraining, the sympathetic form, which puts you into a chronic fight and flight mode and will wreak havoc on both your sleep quality and its duration (usually associated with higher intensity training than the bench pressing session 10min warm-up + 4x80%RM the Rovenda subjects performed) and the parasympathetic form, which is what people usually refer as "burnout syndrome" and will have you sleep hours after hours waking totally unrefreshed, produce quite distinct, yet of many athletes carelessly overlooked sleeping patterns, which - and here lies the culprit, still appear to be one of the best, yet by far not "objective" measures of whether you are "hitting your sweet spot" or are just digging a deep black hole by keep pushing and pushing, when your batteries have long run out of energy (Urhausen. 2002)... but this, my friends is a topic for another blog post ;-)

2x40g, 4x20g or 8x10g of Whey? Which Feeding Strategy Yields the Greatest Net Protein Retention? Plus: What the Results Can Tell Us About Intermittent Fasting on a "Bulk"

In know, after reading the headline you are probably already urgently waiting for the results of the latest study on protein timing, but before we get to the facts, let me briefly announce that this "bolus vs. intermittent vs. pulse" protein study, which is incidentally the result of an international cooperation between researchers from the Nestlé Research Centre in Lausanne, Switzerland, Canadian researchers from the University of Guelph, the Canadian Sport Centre and (you guessed it) Stuart M Phillips' group at the McMaster University, and their colleagues from the Australian Institute of Sport and the RMIT University in Melbourne, will be one of the topics of today's SuppVersity Science Round Up on Super Human Radio.

Other things I hope Carl Lanore and I will be able to squeeze into today's show, which airs, just as every Thursday live at 1PM EST and will also be available as a podcast later today, either right from the nav-bar on the right ("Physical Culture for Your Ears") or at www.superhumanradio.com, are ...

• the latest news on natural nitrate supplementation with beet root juice, 
• how stress and laziness increase breast cancer risk more than hormonal imbalances, and
• how you can prepare your own powerful stevia-based wound ointment  

There is obviously more to the list, but I have learned from past mistakes and won't announce all I have piled up, when I know that's simply not possible to squeeze all of them into a single 1h show ;-)

A note for those of you who are looking for Adelfo Cerame's weekly contest prep blog: Don't worry it's still alive! You must have over-read that he has switched to a bi-monthly format!

Ok, ok... but NOW tell me hod do I have to spread my protein across the day"

While we know already that more is not necessarily better, when it comes to protein intake and that timing plays a significant role with respect to the returns in protein synthesis, and more importantly net protein retention you get for each gram of additional protein you consume, the question how you best spread your roughly 1.5-2.0g of protein per kg body weight across the day is still a matter of contemporary research and bro-scientific debate.

Suggested read: Protein Synthesis "Beyond the 20g Limit: Study Shows Exercise Facilitates 32% Greater Increases in Fractional Protein Synthesis With 40g vs. of 20g of Whey PWO" (click here to read)

What appears to be widely accepted, though, is the notion that both, the ingestion of a slow digesting protein before, and the intake of a fast digesting protein after a workout can effectively increase protein synthesis and net protein retention. If we assume that the combination of both strategies will yield further benefits (this has to my knowledge not been shown yet and is certainly not necessarly the case!), and regard the peri-workout supplementation as a "stand alone" that's not part of the 1.5g-2.0g /kg body weight baseline protein intake, we still end up with at least 80g of high quality protein (for the real light-weights or ladies ;-) we would have to spread in one way or another across the rest of the day.

8 x 10g, 4 x 20g or 2 x 40g? What's "optimal"?

Now, Moore et al. obviously won't have had my allegedly botchy "real-world" scenario on their minds, when they came up with the exact experimental design of their latest study. Still, if we forget about the 20g+ of protein post-workout, I believe none of you will be willing to abandon, their experimental setup fits the framework pretty nicely. After all, the scientists deliberately picked the 12h period after a workout "to standardise and take advantage of the accentuated protein synthesis in the exercised muscle over this period" and investigate three archetypal means of spreading a total amount of 80g of protein across the day: In 2 x 40g servings, 4x 20g servings or 8x 10g serving (Moore. 2012).

Suggested read: "3.2kg of Lean Mass Over Night W/ 40g of Slow Digesting Protein 30min Before Bed!?" (click here to read more)

The 24 male subjects who were advanced trainees working out 4–6 times per week in what the researchers call a "high intensity resistance training regimen" (note: I don't think this denotes a classic low volume HIT regimen) had to

"[...] follow standardized diet for the 72h prior to the trial that provided an energy availability of 45 kcal/kg fat-free mass with a macronutrient contribution 1.5 g protein/kg/d and 4 g carbohydrate/kg/d, respectively. [Moreover, s]ubjects were instructed to refrain from training and other vigorous physical activity during the 72h period."

When the men reported to the laboratory on the testing day, they had refrained from training or performing any other vigorous activity during the 72h period leading to the intervention and had been fasting 10h (over night). In absence of any other information I assume they remained in the fasted state for the subsequent standardized acute bilateral leg extension exercise session (4x10 sets at 80% 1-RM with 3 min recovery between sets), after which they were randomly allocated to receive their 80g of protein from whey as

• pulsed feeding (PULSE), 8x10g every 1.5h; 
• intermediate feeding (INT), 4x20g every 3h ; or 
• bolus feeding (BOLUS), 2x40g every 6h. 

The supplementation regimen was started right after the workout and the protein synthesis, breakdown and net balance were determined based on previously tested and verified procedures (Hartmann. 2006).

Figure 1: Comparison of effect sizes, p-values (remember only p < 0.05 would be a statistical significant difference) and the scientists qualitative inference's based on the effect of feeding pattern on whole body net protein balance (left) and a detailed breakdown of the feeding specific effects on 12h protein synthesis expressed relative to the bolus group (based on data from Moore. 2012)

As the data in figure 1 goes to show you, the results clearly confirm that the pattern according to which you consume your daily allotment of protein does matter, what it does yet not really tell us is how this will translate into a real-world scenario, in which, as I have pointed out before, not having at least 20g of whey / other protein sources after a workout appears almost negligent. The provision of a 20g whey + 10g casein mix right after a workout could, for example, have undone the minimal (and statistically non-significant) advantage in net protein retention of the intermediate feeding group. And that may still have been the case if the latter had been "upgraded"  to a 4x25g whey pattern.

On the other hand, if we wanted to pick on the study design, the "workout" (leg extension) and the absence of other nutrients (or the lack of information about those in the paper?), which could easily have reduced the amino acid breakdown that nullified the advantage the pulse feeding had with respect to its ability to trigger and sustain (over 12h) protein synthesis, would be more relevant points of critique, anyway. That said the "study" at hand is actually only a "short communication", and I am pretty sure there is more to come in the future (it stands to reason that the SuppVersity is the place to go to read about that, right?)

Note: I still maintain that overnight fasting is healthy, and IF probably one of the best, r at least a very effective way to shed body fat, but that does not mean that it should be the only diet strategy in your "nutritional toolbox", in which other tools are probably better suited to pack on slabs of muscle!

(Preliminary) bottom line: The results Moore et al. present certainly don't provide a definitive answer on "the very best" way to time your protein intake (and even if there was an "optimal" way, no single study will ever be able to elucidate it). They do however make one thing pretty clear: My gut feeling that intermittent fasting and here especially those varieties with very long fasting and very short feeding windows, is probably not the best way of dieting to gain muscle. After all, there is no debating that the bolus regimen (2x40g 6h apart!) is trailing behind.

You can certainly tweak and thus optimize it by (a) adding a third meal in between and (b) cleverly using / combining fast and slow acting proteins (cf. "Whey and Casein Work Hand in Hand for Protein Anabolism"), but if you want level playing fields you would have to apply similar tweaks to the more frequent 4 x 20g and 8x 10g regimen as well... and I that would probably restore, if not magnify the difference.

Update on the real world significance of the advantage: I know that SuppVersity readers are smart and therefore was not suprised that only minutes after I posted this article, Steven Arcera objected that long-term studies don't show this advantage. Now, while Steven is right the implicit assumption that this implies that there is no advantage of spreading your protein across meals is false. If we simply take the exact figures from the study, which would be an added ~0.02g/kg body weight in protein retention over 12h, assume (which is obviously not valid) that the protein retention would be identical over the other 12h of the day in all groups and do the math for the study participants who weighed 80kg, this would be an additional 1.6g of protein retention for the whole body (remember this is whole body protein retention) and therfore even in a long-term study of 12 weeks only 134.4g! This would still be 134.4g more than with bolus feeding but would NEVER make a statistical significant difference in any study. And even the 584g "advantage" you would accumulate over a whole year would make it past the p < 0.05 line! So much about "optimal feeding strategies" and the real world outcomes of the latter :-)

References:

• Hartman JW, Moore DR, Phillips SM. Resistance training reduces whole-body protein turnover and improves net protein retention in untrained young males. Appl Physiol Nutr Metab. 2006 Oct;31(5):557-64.
• Moore DR, Areta J, Coffey VG, Stellingwerff T, Phillips SM, Burke LM, Cléroux M, Godin JP, Hawley JA. Daytime pattern of post-exercise protein intake affects whole-body protein turnover in resistance-trained males. Nutr Metab (Lond). 2012 Oct 16;9(1):91.

Doping 2.0 - Myostatin Blocker. We are Finally There! Orally(!) Administered Recombinant Yeast Increases Body Weight and Muscle Composition in Rodent Model.

Image 1: "Wendy" myostatin negative dog
and 7 months old baby of a 24-year old
female former athlete with a family
history of "particular" strength
(image "baby" from Schuelke. 2004)

You have seen those images of myostatin-negative bulls, mice and dogs. Those ugly overmuscled creatures, who cannot even carry the weight of their own musculature. Notwithstanding, you were fascinated by the idea that myostatin blockers, i.e. drugs that inhibit the growth and differentiation factor 8 (GDF8), would turn you into lean, mean mass-monster, but the only results you could find in reliable source were disappointing? Well, you may then get even more excited, when the reliable source your are just studying is telling you that "we are finally there"! Scientists from the Shaan’xi Key Laboratory of Molecular Biology for Agriculture at the Northwest A&amp;F University in Shaan’xi, China have found a way to selectively increase muscle weight in mice by oral administration of a whole recombinant yeast Saccharomyces cerevisiae vaccine (Zhang. 2011).

Before the yeast was administered to the mice at a weekly dose of 120,000,000 yeast cells for 5 weeks, Zhang et al. had cultured the yeast with copper sulfate for 10h to induce the expression of myostatin and ovo-myostatin proteins.

Figure 1: Increases in body weight of 5-week old Kunming mice after 5 weeks of oral or intravenous treatment with recombinant yeast cells (calculated based on data from Zhang. 2011).

As the data in figure 1 goes to show, the oral "immunization" procedure turned out to be more effective than the scientists had even hoped for. Still, vaccination by injection was 7% and 9% more growth promoting for the myostatin (MSTN) and ovo-myostatin (Ovo-MSTN) yeast, respectively.

Figure 2: Additional muscle gain measured in forelimb, hindlimb muscles, as well as triceps brachii and biceps femoris compared to control in 5-week old Kunming mice after 5 weeks of oral or intravenous treatment with recombinant myostatin or ova-myostatin yeast cells (calculated based on data from Zhang. 2011).

In view of both agricultural applications, as well as legal and illegal performance enhancement in recreational and professional athletes, the most important finding of the study yet turns out to be a null-finding: Null, that is the number of pathological change the scientists observed in the course of the study - no abnormal organ growth, muscle weakness and all the other ailments myostatin-null mice, bulls, dogs and whatever poor animals scientists have hitherto genetically modified, usually suffer from:

In  this  study, immunized mice in all groups were found generally healthy looking and  no  significant  damage  in  any  internal  organs. [If one also takes into account the report on the "myostatin baby" by Schuelke et al. (Schuelke. 2004)] these findings suggest  that  immuomodulation  of  myostatin  is  safe in  both  laboratory  animals  and  human.

Image 2: While the mice did gain significant
amounts of weight (esp. muscle) they are
completely healthy and do by no means
look as bulky as genetically modified dogs,
bulls and co. (image from Zhang. 2011).

If you look at the mice in image 2, it is in fact hard to tell, which of the mice received the control and which the myostatin yeast and that despite the fact, that - assuming similar effects in adolescent human beings - the average sleeve size of humans who have been immunized with this yeast would increase from ca. 32cm to ca. 43cm! That being said, it is unlikely that the "immunization", which has your body produce antibodies against myostatin and thus blocks the inhibitory effect of the TGF beta protein on muscle growth, will produce such profound results in adults, whose bodies obviously are not primed to growth in the way the bodies of children or adolescents are... but hey, there are enough aspiring young athletes in the Chinese Olympic Team to see preliminary results in 2012 (hoops, I think this was not 100% politically correct ;o)

SuppVersity EMG Series - M. Deltoideus, M. Infraspinatus, Supraspinatus and Teres Minor: The Very Best Exercises for Broad Shoulders and Capped Delts

Image 1: The muscles of the deltoids (red) on the
front (left) and back (right) of the body and the
rotator cuff (violett), the group of muscles
and tendons that stabilize the shoulder.

I don't know about you, but somehow I feel sad that this is already the last installment of the SuppVersity EMG Series. While it certainly was a hell lot of work to compile all the information, I am very pleased that (a few exceptions aside) you, the 'students' of the SuppVersity; appreciate and put into practice some of the information, I am putting out here. That being said, it is actually quite fitting that the series ends on a body part, even bodybuilders hardly ever stop fine-tuning: the complex musculature of the shoulder,

• the anterior, lateral and posterior part of the m. deltoideus, also known as the pars clavicularis, which attaches to the clavicle, the pars acromialis attaching to the acromion and the pars spinalis that is directly attached to the spina scapulae,
• the rotator cuffs, which comprise the m. infraspinatus, which arises from beneith the scapula at the fossa infraspinata scapulae and facilitates internal rotation, the m. supraspinatus, which is situated right above the former and is involved in the lateral adduction of the arm, and the m. teres minor, which is attached laterally to the scapula at the margo lateralis scapulae and figures in the abduction of the arm; the m subscapalaris, which completes this commonly overlooked muscular quartet attaches to the inner part of the scapula and facilitates internal rotation, abduction and adduction of the shoulder.

Of the two muscle groups the former, i.e. the "delts", is the one that will give your that broad-shouldered look, everyone is striving for, while the latter constitute a necessary yet commonly overlooked prerequisite to build it. Eventually the muscles of the rotator cuff provide the stability which is necessary to properly execute those front presses, lateral rises, reverse flys and all the other common exercises for round, muscular shoulders! It is vitally important to keep this synergism in mind, when designing a routine - and if the risk of shoulder injuries due to underdeveloped stabilizer muscles does not shock you, maybe the information that a strong foundation in form of properly trained rotator cuff muscles will help you with "increasing your bench", so that the next time a bro asks you "Hey bro, how much ya bench!" you may well impress him with a new personal best (in case that is what you're training for ;-)

Chest	Biceps	Back	Core	Legs	Triceps	Shoulders
Navigate the SuppVersity EMG Series - Click on the desired body part to see the optimal exercises.

But enough of the mourning and mocking, let's get some meat on your shoulders, or rather, let's get to the meat and potatoes of shoulder training - the SuppVersity proudly presents: The most effective exercises, as measured by electromyography (10 male resistance-trained subjects, mean age 22y, mean body-fat 13%; data from Boeckh-Behrens & Buskies. 2000) for building massive delts and a powerful rotator cuff...

I. The Best Exercises for the Anterior, Lateral and Posterior Parts of the Delts

Image 2: Turns out the injury-prone neck
press is the most versatile delt-exercise as
it hits both the anterior, as well as the lateral
part of the delts about as hard
(image from sportkrachtfitness.nl)

I probably will never get tired of telling you that complete isolation, as in "petri-dish" experiments, is nothing you will be able to achieve in the gym - not even if you use one of those fancy new devices, the name of which would suggest that they would facilitate exactly that ;-) In the real world (and, believe it or not, the gym is part of it) your muscles will always work synergistically to move the weight from point A to point B. It is however very well possible to influence which muscle group and even which individual muscle takes the lion's share of the workload by selecting the right exercises and / or manipulating the way you perform a given exercise.Always remember this, when you take a look at the following list of the "most effective exercises" (correctly I should say the exercises with the highest EMG activity).

for the lateral part... Lateral raise - DB, internal rotation (view) Reverse fly - machine, ext. rotation Neck press - BB, seated for the posterior part... Reverse fly - machine, int. rotation (view) Reverse fly - DB, internal rotation

for the anterior part... Military press - BB, seated Neck press - BB, seated Lateral raise - DB, internal rotation Bench press - BB Front raise - DB, external rotation * BB = barbell; DB = dumbbell

Figure 1: EMG activity of anterior, lateral and posterior part of the m. deltoideus during selected exercises relative to the military press (anterior), the DB lateral raise (lateral) and the DB reverse fly (posterior); calculated based on data from  from Boeckh-Behrens & Buskies (2000)

The EMG data in figure 1 confirms what trainers all over the world have been propagating for decades. A pressing movement for the front delt (anterior part), some lateral raises for the lateral part and a few reverse flys for the posterior delts is all it really takes to built "cannon-ball delts". Another common wisdom, which says that front raises were among the most effective exercises for the anterior deltoid, on the other hand, gets busted. Even done with your ams externally rotated, the DB front raise is 41% less effective than the "gold standard", the barbell military press. A possible reason (and major drawback of all EMG data) for the "inferior" activation of front delt by the DB front raise are significantly lighter loads compared to the BB military press. If the subjects had used 120lbs for the military press, but only 25pounds per DB for front raises, for example, the muscle activity per pound of weight for the DB front raise would in fact have been roughly tree times higher - 929µV/120lbs=7.71 for the BB military press vs. 548µV/25lbs=21.92 for the DB front raise. That being said it stands out of question that, within a volume program, there certainly is a place for an isolation exercise such as the DB front raise, even if it is not a classic "mass building" exercise, the outstanding characteristic of which is maximal muscular overload, after all.

Image 3: With its naturally arched
movement, the DB shoulder press
may be a viable, if not preferable
alternative to the BB military and
BB neck press (image everkineti.com)

Exercise tip: While the respective EMG values for dumbbell exercises have not been measured in the study, it is very likely that exercises such as the DB overhead press provide an extra stimulus over their barbell equivalent that is related to the more natural arch of motion, where you get a good stretch at the bottom and can really squeeze the muscles in the contracted position, when the dumbbells approach (they do not cling!) each other at the top of the movement.

That being said, the DB overhead press is also a viable alternative for the BB neck press as the position center of gravity is more in line with your head throughout the movement. It may thus be assumed that the the stimulus shifts away from the front and towards the lateral deltoid, as it is the case with the neck vs. the military press.

Form, I cannot emphasize that enough, becomes more and more important with lighter weights, and as your shoulder is peculiarly prone to injury and generally much weaker than your legs, for example, it is not only advisable, but simply a matter of physical limitations to use lighter weights. That being said, the previously cited example of the DB front raise shows that lighter weights do not equal inferior muscle stimulation, as - done properly - respective isolation exercises generate way more torque per pound of weight you are handling than their mass building counterparts.

Figure 2: Reduction in EMG activity of selected variants of the DB lateral raise and the reverse fly relative to lateral raises with external rotation, DB raises with 90° arm/torso angle and internally rotated machine reverse flys; calculated based on data from  from Boeckh-Behrens & Buskies (2000)

Form does yet not only determine overall intensity, the way you are doing your shoulder exercises also has a profound influence on the degree to which the three parts of your deltoids are activated. Doing DB lateral raises internally rotated, for example, reduced the activation of the lateral part of your delts by -16%, using a neutral, i.e. a hammer grip (thumbs facing up) was associated with a -12% reduction in EMG activity. In the case of the DB reverse fly the use of an arm to torso angle of 45°, instead of 90°, reduces the load on the lateral part of the deltoids by -29% and gripping the handles of the reverse fly machine from the out- instead of the inside (external vs. internal rotation of the arm), takes away -20% of the stimulus (cf. figure 2).

Dessicating the Lateral Raise

If you make good use of what you have learned at the end of the previous paragraph, you can improve the load on the target muscle, while handling lighter weights and decreasing your risk of injury - I know, the big weights are more impressive, but after all what's the use of using the biggest weights, if you are not making progress, both strength- and size-wise, because of improper form? I mean, it is one thing to cheat on the last 1-2 reps of a set in order to squeeze out the very last drops of gasoline from your muscular tanks, it is however something completely different to compromise form, just to be "the guy who lifts the heavy weights". There is hardly any movement, where this becomes so obvious as with the DB lateral raise. If you do not do it yourself, you certainly know someone who grabs the 50lbs dumbbells, holds them vertically before his groin and then powers, or I should say, "rips" them up to his sides, lets them bang down and starts all over again until, after he eventually racked the weights, he grabs his shoulder or wrist in agony, yet not without the pride of having used a heavier weight than the guy next to him.

Note: The following analysis is based on a VERY simple mechanical model and does not consider factors such as increased load per square area of muscle fiber in the stretched position, effects of static or complete contraction etc... Notwithstanding, if you like the following part of this write-up, please spread the word (via Facebook, Twitter, etc.) and let me know (in the comment section or the SuppVersity Facebook page) that it would be worth the effort to do similar and even more depth analysis in the future!

You already know from the previous paragraphs and the EMG data in figure 2, that it is imperative to keep the arms externally rotated, i.e. to pretend you were trying to pour out an imaginary liquid from the dumbbell at the top of the movement, if you do not want to lose 16% of the muscle tension in the first place... Well, but what about the aforementioned guy who does not even get the chance to think about pouring out any liquid other than that in his shaker bottle, when he is performing his ballistic weight exercises? Which of his mistakes, do you think compromises the effectiveness of the lateral raise most?

1. Flexing the elbow too much (often up to 90°) and thus reducing the lever? Or,
2. Not raising the dumbbells to shoulder height, i.e. keeping the angle between arm and torso <<90° (often <<70°)

Well, from a physical perspective, which always provides a very selective and (over-)simplified view of reality, the answer would be "1. flexing the elbow too much". Surprised?

Figure 3: Effects of arm/torso angle and elbow flexion on torque during the DB lateral raise
(data calculated based on a very basic physical model)

While raising the dumbbells to 75°, takes away less than 5% of the torque (cf. figure 3), flexing the elbow to 90° reduces the torque on the lateral parts of your deltaoids have to overcome by a whopping -50%! Think about that, when you look at the guy with the 50lbs dumbbells the next time you are at the gym. Chances are that you, with your 30lbs DBs are way stronger than he is, as long as you do not give in and reduce your elbow flexion more than those 15% that relieve some of the stress on the joint, but only minimally reduce the torque on the muscle.

II. The Best Exercises for the Rotator Cuff

I hope that, over all that you have learned about delt-training by now, you did not forget, what I mentioned at the very beginning of this installment of the SuppVersity EMG Series: Rotator cuff training equals active injury prevention. While most trainees do not even feel them working, the muscles of the rotator cuff are crucial for the stability of the most flexible and volatile joint in your whole body, your shoulder. It is imperative for these largely overlooked and often undertrained muscles to hold the ligaments and bones of your shoulder in position so that your other muscles such as the deltoids or the pectoralis can do their job. To build a strong m. infraspinatus, m. supraspinatus and m. teres minor, is thus also the foundation of building a "bigger bench" to impress your bros at the gym. If you don't believe that, you may listen to strength coach Charles Poliquin, who has the following anecdote to tell:

One of my pro hockey players, Jim McKenzie, improved his 14-inch, close-grip bench by 51 pounds in 12 weeks, from 280 to 331 pounds, by focusing on rotator cuff strength.

And though I doubt the universality of Poliquin's "research", as far as the non-athletic regular gym-goer is concerned, it is certainly noteworthy that his years of experience in working with athletes have told him that "rotator cuff strength should be about 9.8 percent of what you can lift in the bench press [for] pain free bench pressing". That means, if you are benching 200lbs you should not wonder if your shoulder begins to hurt, if you are not able to use 20lbs dumbbells when doing external rotations lying on a mat on the floor ...

Figure 4: EMG activity of the major muscles of the rotator cuff during selected exercises relative to the DB external rotations done lying sideways on the floor; calculated based on data from  from Boeckh-Behrens & Buskies (2000)

A pros pos external rotations as the data in figure 4 goes to show this is by far the best isolation exercise for the muscles of the rotator cuff. In essence, it does not really matter if you want to do them with a dumbbell standing, lying on the floor or with an elbow on a bench, or if you prefer doing them using a cable pulley. The differences are negligible, in view of the huge difference improper exercise execution would make - so you better do an exercise you like with light weights and feel the muscle working than an exercise that has been shown in study XYZ to be the most effective with a weight you can hardly handle and where you do not feel the target muscles working. This, by the way applies to the static doorway pushback, which is basically an "inverted pectoral stretch" where you push with the backside of your arm (angle arms/torso 90°) backwards against an immobile object like a doorway, as well. If you do not feel like this static exercise is working for you chose a different one.

Image 4: DB lateral raise with
arms 30° horiz. adducted for the
m. supraspinatus (Jobe. 1986)

Isolating the m. supraspinatus with lateral raises: According to Jobe & Moynes (1986) the DB lateral raises performed with a 30° horizontal adduction of the arms fully isolates the m. supraspinatus if you rotate your shoulders so that your palms are facing the floor (the good old "emptying the bottle" technique). Doing 1-2 sets of lateral raises this way certainly is a time efficient way of incorporating a strengthening exercise for the upper part of the rotator cuff into your routine. You will have to use much lighter weights than on regular lateral raises, though.

III. Conclusion- Three Plus One Equals Injury-Free Strength and Size

An imperative prerequisite for building impressive deltoids and thus broad, rounded shoulders is a stable foundation in form of strong rotator cuff muscles, if you neglect the latter you will either plateau or - even worse - injure yourself sooner or later. That being said, especially your front delts are hit very hard during pretty much all pressing movements for chest and triceps, it is thus neither really necessary nor advisable to do more than one (if any) "isolation" exercise in the form of a compound movement like the barbell or dumbbell military press, a movement, which by the way will also greatly help to bring up "the upper chest" many bodybuilders feel they are lacking. If you complement this basic "mass builder" with some lateral raises and reverse flys, the one and only thing that is really left to do on "delt day" is a rotator cuff exercise of your choice and you are ready for some highly anabolic rest and recovery ;-)

An EMG-Optimized Routine

Image 5: You can rotate in some
Arnold Presses, if you feel you did
not hammer your front delts heavy
enough with the military press

There is of course a myriad of ways of combining the individual exercises, my personal recommendation for overall deltoid development and rotator cuff strength (based on EMG measures) would yet be as follows...

1. Military Press - BB or DB seated, 6-8 reps
2. Lateral raise - DB elbow-flexion <15°(!), 10-12 reps
3. Reverse fly - machine or DB, internal rotation, 10-12 reps
4. External DB rotations - lying on the floor, 12-15 reps

You may notice that I do not make volume (i.e. set) recommendations. This is due to the fact that I found that everyone has to find what works best for him / her in terms of optimal volume, training frequency and body part splits. This may also change over time / according to lifestyle factors / nutrition and supplementation.

SuppVersity EMG Series - Rectus Abdominis, Obliques and Erector Spinae: The Very Best Exercises For Sixpack Abs and a Powerful Midsection

Image 1: There is more to a strong core
than just the m. rectus abdominis aka
'the abs' (red);  its imperative to train your
obliques (blue) and the muscle strands
of the erector spinae muscles which
stabilize your spine (violette)

"6 weeks to 6-pack abs" - although we all know that this is unattainable for the majoritity of beer-bellied casual Men's Health reader, headlines like that still make the sales of today's fitness magazines go up. On the other hand, Charles Atlas, John Grimek, Ray Parks, Eugen Sandow and the other fathers of physical culture would certainly turn in their graves, if they saw the metrosexual size zero bans on the covers of respective 'lifestyle' magazines and read about the 'cult of sculpted abs' that has befallen their 'grandchildren'... well, I guess you don't care about those 'grandpas', let alone my rants, and still want your sixpack to shine in its full glory on the next spring break, no matter what? Ok, but beware, even the best exercises won't help, as long as your glorious rectus abdominis is covered by an unaesthetic layer of adipose tissue - the key to sculpted abs is dieting! As far as core training is concerned, it is imperative to understand that building a stable core, which is a major yet often disregarded prerequisite for lifelong mobility, is not only about 'ab-training'. Its about training all those exterior and interior muscle strands that keep you upright:

• the m. rectus abdominis (image 1, red), which consists of two parallel muscle strands that run vertically on each side of the anterior wall of the human abdomenis and are often simply referred to as 'the abs'
• the external and internal oblique muscles (image 1, blue),  which pull the chest downwards and compress the abdominal cavity (external) also have a limited action in both flexion and rotation of the vertebral column (both) and cover the transverse abdominis muscles, which are located beneath the obliques and help to compress the ribs and viscera, thus providing thoracic and pelvic stability
• the muscles of the erector spinae (image 1, violette), which are of paramount importance to your life, because they stabilize and protect your spine

Now that you know what this issue of the SuppVersity EMG Series is all about, I do not want to put you on the abwheel, ah... pardon, the rack any longer, but just in case you agree with me that a great physique is not about having abs alone, you may want to check out some of the other parts of this series, as well.

Chest	Biceps	Back	Core	Legs	Triceps	Shoulders
Navigate the SuppVersity EMG Series - Click on the desired body part to see the optimal exercises.

The SuppVersity proudly presents: The most effective exercises, as measured by electromyography (10 male resistance-trained subjects, mean age 22y, mean body-fat 13%; data from Boeckh-Behrens & Buskies. 2000) for your abs, your obliques and your the stabilizer muscles...

I. Training the m. rectus abdominis (aka 'the abs') & the oblique muscles
 

I want to begin with a word of caution, although 'the abs' do in fact comprise two muscle strands, the two strands ran vertically and parallel to your spine. The assertion that there are 'upper' and 'lower' abs is thus not supportable from a purely anatomical point of view. If you do ab-exercises and even more so, if you do full body movements like squats, deadlifts or military presses, the muscle strands of your rectus abdominis (as well as your obliques and the erector spinae muscles) will always be engaged as a whole. As it is the case for the latissimus dorsi, another of the large muscle groups in your body, it is yet possible to put a special emphasize on the upper or lower part of your abs. Remember that, when you read about the best exercises for 'upper' and 'lower part' of the m. rectus abdominis in the following overview.

Six or eight packs - genetics or training? It is an urban or, I should say a 'gym myth' that you "progress from a six- to an eightpack" by training your abs until they hurt. The way your 'abs' look, which includes the number of packs, is determined by genetics and body fat level. The latter, by the way, is the reason why so many trainees believe they would just have to keep training until - almost magically - the 7th and 8th pack would pop up. While this does work for many people, it is not because of training-induced hypertrophy, but rather due to atrophy - adipocyte-atrophy, or fat loss to be precise. Especially the lowest of the six or eight packs tend to be covered by a very stubborn layer of stress-fat, that's why many peple begin to see them, when their training advances and their body fat levels drop.

The EMG data from Boeckh-Behrens & Buskies also goes to show that even in the case of the rectus abdominis and the external and internal oblique muscles, true isolation is impossible. Everytime you engage in any type of core exercise both the central, as well as the lateral stabilizers or, in other words, the abs and the obliques will be working.

Figure 2: EMG activity of m. rectus abdominis (upper part), m. rectus abdmonis (lower part) and oblique muscles during twelve selected core exercises relative to muscle(-part) specific reference exercises as indicated by the asterisk '*' (data adapted from Boeckh-Behrens & Buskies. 2000)

The graphical illustration of the relative EMG activity of twelve selected core exercises confirms the statement that any given exercise for the 'abs' will inevitably also involve a certain degree of oblique activity. It is however also quite obvious that trainees can easily emphasize a certain muscle group (or part) by selecting the appropriate exercises from the following top 12:

Table 1: Top 12 ab- and oblique exercises; ranking according to Boeckh-Behrens & Buskies, 2000

It is quite obvious that with a set of 3-6 exercises (I marked the top exercises in green) you can effectively train the whole anterior part of your core and still keep enough variety to avoid getting bored - and, what's probably even more important, to "keep your body guessing". It is yet also obvious that much more than it is the case with exercises for other body parts, there is huge inter-personal variety in terms of which ab-exercises work best for whom. Therefore I decided to give you some additional data on the exact mean ranks of the specific exercises - something I omitted in the previous issues of the SuppVersity EMG Series simply because (with the exception of the chest, where I mentioned it in the text) the mean rank and the mean EMG activity toplists would have been identical, anyway.  

Perfect form counts, especially on the advanced movements

Image 2: Trainees tend to (ab-)use the psoas major and thus decrease the activation of the 'abs', when doing leg raises, sit-ups etc. (image by Beth ohara @ Wikipedia)

A perfect example of improper form compromising exercise efficiacy is the hanging leg raise, where, in the case of the upper part of the m. rectus abdominis, you can see that the exercise must have produced an extraordinarily high EMG activity in some, and a rather mediocre muscular activation in other subjects. Otherwise the ranking according to mean EMG for the exercise over all subjects (rank 2) and the mean exercise rank for the individual (rank 3) would be identical. Those of you who know how to do the exercise properly will know that even under professional supervision many trainees fail to actually flex their abs and thus train their psoas major (cf. image 2) instead of their abs, when they hang like a flabby sack from the bar and swing their legs up and down. A similar shift away from the m. rectus abdominis and towards the psoas, occurs in all ab-exercises where your legs are held in a fixed position, the most dreaded example being the classic sit-up, from which generations of trainees developed a hollow back (hyperlordosis); a pathology that cannot only entail lower back pain, but will also make your abdomen stick out even further, the result of which would be an untrained pair of abs that "sticks out" not in the intended metaphorical, but in the unwanted literal sense. Don't get me wrong, I am not generally against doing sit-ups, let alone leg raises (they are in fact among my favorite core exercises), I just want you to make sure, you are doing them right, so that you...

1. do not get hurt,
2. do not develop muscular imbalances, where despite or rather due to improper ab training your m. rectus abdominis becomes the weakest link and thus
3. do not put yourself at danger of developing a (painful) hollow back and an untrained pair of abs on a portruding abdomen

Therefore I would advice beginners to follow exercise tip #1 to build up the strength of your abs and learn how to do the hanging leg raises properly before you wrack havoc on your lower back.

Exercise tip #1 - the road to correct hanging leg raise: Done properly, hanging leg raises are the king of all ab-exercises, which does yet require practice and a core that is already pretty strong. Therefore I would suggest beginners start out with the lying leg raises with their hands or one of those pillows under their lower back for lumbar support. By trying to press their hands / the pillow into the floor in the course of the movement, they will develop the core stability that is necessary to progress

1. from the supported to the unsupported lying leg raises
2. from leg raises on the floor to leg raises on a decline
3. from decline leg raises to hanging leg raises

Note: It is neither necessary nor advisable to fully extend your legs during any of these exercises. Doing any of these movements with your legs straight tends to shift the relative workload away from your abs and towards the psoas major, and it increases the overall load on your lower back - the same applies for the dreaded sit-ups with leg-fixation, as well.

I suppose, some of you may be disappointed, that exercises like the cable crunch or your favorite abdominal trainer have not made it to the list. While I think that many of the ab-machines share the same problematic psoas major activity as improperly executed hanging less raises or sit-ups, I count the cable crunch among the most effective ab exercises one can do.
 

Image 3: Exercise variation is key, especially for advanced trainees, who do not want to hit a plateau. Therefore, even self-proclaimed 'pros' should not back off from stability exercises like the side plank, which is the 2nd most effective exercise for the oblique muscles in the top 12 (image from www.everkinetic.com)

That being said, EMG data, no matter how scientifically objective it may seem, should never have you give up what works for you. Ab training, just like everything else you do in the gym, is not about doing, but about feeling the movement. Or, in other words, if the consequence of extending your arms behind your head is that you stop feeling how your upper abs are contracting, chances are that the purported #1 exercise for the upper part of the m. rectus abdominis, the crunch with extended arms, is not for you. The possible reasons for that are manifold, with the two most likely reasons being that you're simply not doing the exercise right (remember: doing crunches is not about raising your head off the floor ;-) and/or the exercise intensity is not appropriate for your training level. The latter is an oftentimes overlooked factor which hampers progress in beginners and advanced trainees, alike. I've hinted at this in exercise tip #1, already rookies need to build a foundation before they start doing 'advanced' exercises such as hanging leg raises - you would not tell a toddler who has just taken his/her first steps to go and compete in the Olympic 200m race, would you? In the same vein, you will probably get neck and lower back problems if you start doing 100s or 1000s of 'ballistic' sitpus, where you're virtually trying to lift your upper body from the floor by pulling it up from your ears or the back of your head. Believe me, many of the pot-bellied weekend warriors I see doing this type of "ab training" would be better off doing a single set of 6-12 properly performed crunches with peak contractions. Unfortunately, many of them cannot do even one of those, because their m rectus abdominis is simply too weak to lift their massive upper body off the floor. Similarly, I see some advanced trainees still perform an hour-long crunch workout, carefully making sure that they perform at least 50 reps of each and every funky move they have ever seen in one of those stupid fitness magazines - come on guys (interestingly only few girls seem to be stupid enough to do so), I know you have not been making progress in years... always remember. progress, or rather progressive muscular (not lumbar ;-) overload that is the key to success in whatever you do in the gym.

Exercise tip #2 - Exercise intensity and the myth of high-rep-training for abs: In that it is important to accept that they may be no limit to the number of 1.25 pounds of weight you want to try to add to the bar every week, there certainly is one to adding another rep to the number of crunches, leg raises or side-bends you perform. In the case of the crunch, for example, the beginner would first have to practice doing the basic crunch right, to feel his abs working, to be able to stop half-way up or down and deliberately contract his muscles and to "peak-contract" his m. rectus abdominis until it hurts. The advanced trainee, on the other hand, will have to refrain from increasing the number of reps beyond a max of 20 reps. Instead, they should focus on increasing torque by either

• varying the position of his arms - beginner: hands support lower back; intermediate: hands on the chest / at the sides of your head; advanced: arms extended behind the head
• adding light weights - e.g. holding a light dumbbell in your hands when you do the crunch with your arms extended behind your head, on the leg raises you could use some of those weight straps for the ankles, etc.
• switching to more advanced exercises - properly executed hanging leg raises, for example, activate the upper part of the abs almost as effectively as crunches; they are the #1 exercise for the lower abs and #3 for the obliques; but they are difficult to do and require an already fortified core (cf. exercise tip #1)

Rookie or pro, training abs is not essentially different from training any other muscle group - its about feeling the contraction not about lifting the weight (your body), let alone impressive rep counts and without proper rest, i.e. at least 48h to the next ab workout, the m. rectus abdominis will rather atrophy than shine in full glory.

If you are doing the right exercises and increase reps and then weights, incorporate advanced exercises and still do not see progress, I can tell, without even even knowing what you had for breakfast that it ruined your efforts in the gym. Having great abs is 75% diet and 20% whole body training and 5% ab training, remember that whenever you get the idea that doing another 100 sit ups or training your abs every day (every other day = max) would magically melt the fat away... you better save the time for some serious squatting, deadlifting or high intensity interval training if you want your abs to shine in their full glory. II. Training the erector spinae (focus on lumbar part) Contrary to having "great abs", which is probably the #1 on the wish-list of trainees in gyms all around the world, impressive erector spinae muscles appear to be way less popular in a world where the divide between morbidly obese exercise dyslectics and ripped exercise freaks is ever increasing. And while the former simply ignore that a strong lower back may save them from a whole host of minor ailments of will experience on top of heart disease, diabetes and Alzheimer's in their later life, the latter keep looking at their sixpacks and simply take for granted that the literal flipside of what they consider the epitome of a fit and healthy body (their sixpack) would look alike. Sometimes this may be the case, more often than not, those are however the same guys and girls who neither squat or deadlift, because they falsely assume that this would make them bulky. The EMG data by Boeckh-Behrens & Buskies goes to show that, due to this commonly held misconception many trainees miss out on the two most effective (hard-)core exercises.

Image 4: Variations of the deadlift (here the romanian deadlift) are still the most basic lower back movements

The best exercises with standard equipment

1. Leg raises on the lying leg curl machine*
2. Classic squat
3. Hackquat machine
4. Deadlift (100% body weight)
5. Romanian deadlift (50% body weight)
6. Partial Deadlift (50% body weight)

* The leg raise on the lying leg curl machine is done with your hamstrings flexed by just rising your quads off the pad with the muscles of your lower back - the move is quite tricky and I personally would suggest you refrain from doing it, when you do not have any health issues that hinder you from doing squats and deadlifts

Figure 3: EMG activity of erector spinae (lumbar part) during six selected core exercises with standard equipment relative to the "king of all exercises", the squat (data adapted from Boeckh-Behrens & Buskies. 2000)

I consider it noteworthy that the decrease in weight on the deadlift (done to avoid injury) obviously takes away from the EMG activity Boeckh-Behrens & Buskies were able to measure. It is thus highly likely, that

1. the deadlift is the most taxing and at the same time most stimulating exercise for the muscles of the erector spinae, and
2. the partial romanian deadlift (legs straight) is probably even more taxing and thus more stimulating than the "classic" deadlift (the EMG data seems to confirm that, as the subjects lifted 2-times the amount of weight on the classic deadlift, yet the muscular activation increased by only 76%)

That being said, at least one of the two fundamentals of true strength, i.e. deadlifting or squatting, should be part of everyones routine - no other exercises will fortify your core and whole body in a similar fashion as these two. Add one, maximal two of the following body weight exercises and your lower back is ready to roll... pardon me, to lift!

Image 5: The flutter kick with endcontractions & the pelvic lift, which is similar to the lying hip extension with the exception that you bend the free leg (100°) turn to be slightly more effective than the good old reverse extensions

The best body-weight exercises

1. Flutter kicks, prone position, with peak contractions
2. Pelvic lift, knee angle 100°
3. Hyper-/reverse extensions
4. Bird (plank position, no arm activity)
5. Sitting upright arms spread like an eagle

I find it quite telling that just sitting 100% straight on a bench with your arms in the eagle position (90° between upper arms and torso, arms slightly bend, so that your palms are facing upward / has something of a preacher ;-) still produces 25% of the activation classical reverse extentions do. This goes to show you how demanding everyday life is for your lower back!

Figure 4: EMG activity of erector spinae (lumbar part) during five selected body-weight exercises relative to the well-known hyper-/reverse extensions (data adapted from Boeckh-Behrens & Buskies. 2000

III. Conclusion: 3 basic moves for a fortified core!

I suppose, there were not too many big surprises in this issue of the SuppVersity EMG Series, or at least I would hope so... you did not believe all those exotic contortions Men's Idiocy & co invent each spring to attract new readers would be worth doing. Did you? Some sort of crunch, some leg raises and one of the core (this refers to both your core as well as the core of your workout) exercises, i.e. deadlifting or squatting max 2-3 times a week is all it takes to fortify the center of your body. If you want the additional bonus of a shiny six (or eight-)pack, do at least as many squats and deadlifts as you do crunches, add in some HIIT (high intensity interval training) and stick to your diet.

Image 6: You asked for it, here is the
info - the ab-roll-out probably is probably
among the most effective ab-exercises, as well.

User requested update: "Dr. Andro What about the Ab-Roll-out?" This question has now been posed twice and not only because one of the persons who asked was my Buddy Duong, I dug a little in the archives of exercise sciences and came up with a study that compared 8 Swiss ball exercises (roll-out, pike, knee-up, skier, hip extension right, hip extension left, decline push-up, and sitting march right) and 2 traditional abdominal exercises (crunch and bent-knee sit-up) and found that EMG signals for the upper and lower part of the m. rectus abdominis, as well as the obliques were "greater compared to most other exercises". In that it has to be said that the movements were performed for 5 reps only and that even the authors remark that higher / more diverse repetition ranges could have influenced the overall results they summarize in their conclusion as follows: "The roll-out and pike were the most effective exercises [in this study! a direct comparison of the EMG data with the one from the Boeckh-Behrens Buskies study would of course be invalid] in activating upper and lower rectus abdominis, external and internal obliques, and latissimus dorsi muscles". Bottom-line: Daron, Duong & the rest - keep doing your roll-outs, if you like them ;-)

An EMG-optimized routine

Image 7: The kneeling cable crunch (image shows seated) is one of my favorite exercises for the m. rectus abdominis; although the authors did not measure EMG activity, Boeckh-Behrens & Buskies explicitly mention this ab-exercise as being particularly effective for advanced trainees (image from everkinetic.com)

There is of course a myriad of ways of combining the individual exercises, my personal recommendation for overall core development (based on EMG measures) would yet be as follows*:

1. Crunches < 20 reps; vary arm / hand position or add weight + peak contractions to build intensity without going past max. 25 reps
2. Leg raises < 15 reps; vary according to exercise tip #1; do at least one of your sets with your legs / torso rotating sideways, alternate left and right
3. Deadlift variety 10-12 controlled reps; select the deadlift variety you feel isolates your lower back best

* "<" indicates that you should not be able to perform another rep with perfect form You may alternate that with:

1. Kneeling cable crunch < 15 reps; add weight whenever possible
2. Side bends < 15 reps; add weight if necessary, be cautious not to bend over or go into hyperlordosis
3. Hyperextensions** < 12 reps, with proper form + peak contraction; add weight if necessary

** I chose the hyperextensions over the other two movements, because you can easily add weight by grabbing a plate and holding it before your chest You may notice that I do not make volume (i.e. set) recommendations. This is due to the fact that I found that everyone has to find what works best for him / her in terms of optimal volume and training frequency. This may also change over time / according to lifestyle factors / nutrition and supplementation.