Study Probes Muscle Building Effects of Vitamin D in Young and Old and Finds None, but Relative Strength in Old and Fiber Composition & Myostatin in Young Muscle Respond

Old or young, who is going to benefit and who is going to benefit most from vitamin D supplementation during a 12-week resistance training regimen. Unfortunately, we don't have an unambiguous answer - yet!?

Ok, I have to admit, I could have kept up the suspense by not giving away the main result of Jakob Agergaard's and colleagues' latest study in the headline, already. On the other hand, by giving away the most relevant information in the headline, I can make sure that future google searchers will immediately refute the claim that "vitamin D is a powerful muscle builder" - it is not. What it may very well be, is a vitamin that is necessary for your long-term success.

This is still much different from what you may conclude solely based on the associations that exist between low vitamin D and all sorts of ailments, though. Evidence that vitamin D(3) supplements are able to reduce the risk of bone fractures, diabetes, cardiovascular diseases, cancer, depression, osteoarthritis, multiple sclerosis, and other immune-related diseases is still preliminary. Very unfortunate in view of big research dollars that have been spent without yielding D-finite results and hundreds of more or less practically useless observational studies.

There are many ways to get your vitamin D - learn more the SuppVersity

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Vitamin D For Athletes!

Vitamin D Helps Store Fat

I was thus very happy to see that the scientists from the University of Copenhagen did not content themselves with correlating the individual gains of their young and old subjects with the corresponding vitamin D levels. Instead, they designed a randomized controlled trial in which they "investigate[d] whether vitamin-D intake during 12 weeks of resistance training has an additive effect on muscle hypertrophy and strength"  (Agergaard. 2015) in Healthy, sedentary young (aged 20–30 years) and elderly (aged 60–75 years) Caucasian men living within the local community in Copenhagen:

"We hypothesized that intake of vitamin-D plus calcium would improve the outcome of three months of resistance training in healthy untrained individuals resulting in greater muscle strength and hypertrophy compared to a training control-group supplemented with calcium alone (placebo). Moreover, we hypothesized that resistance exercise would increase the mRNA expression of VDR and CYP27B1. The study included a group of young and a group of elderly individuals to elucidate a possible blunted hypertrophic response in the aging muscle"  (Agergaard. 2015).

The study took place at Bispebjerg Hospital, Copenhagen, Denmark (latitude of 56°N). Inclusion was continuous from November 17, 2010, to December 21, 2010, and the last subject completed the study on April 25, 2011. Thus, the study was conducted in a period of low UVB irradiation from sunlight. The risk of interference by uncontrolled sun-exposure was thus low. About as low as I suppose some of you will say the supplementation dose was. The latter consisted of either

• placebo supplementation with 800mg of calcium per day, or
• vitamin D + calcium at a dosage of 48µg (1920 IU) vitamin-D 3 + 800 mg calcium/day

that was administered in two servings, with one tablet containing 10 μg vitamin-D 3 + 400 mg calcium and one tablet containing 38 μg vitamin-D 3 + 400 mg calcium and had to be taken with meals (this increases absorption | learn more).

You're too lazy to read and want some extra-information, also on the topic of fat cell cellularity, obesity and body weight regain (yo-yo effect?) - Download yesterday's installment of Super Human Radio and listen to my interview an add-free version right here!

The scientists probably would have dosed higher, but since the maximum advisable daily dose according to the Danish Health and Medicines Authority is 50 μg, i.e. 2000 IU, they probably felt that their hands were tied.

Figure 1: Flowchart showing a young and b elderly subjects from first contact to end of study (Agergaard. 2015)

All subjects who had been randomly (double-blind) assigned to the respective group had to follow the same standardized workout routine consisting of a total of 36 training sessions (12 weeks with 3 sessions/week) with 5–10 min warm-up on cycle ergometers followed by resistance training exercises of the lower extremities (only!) performed in commercial knee extension and leg press devices (Technogym, Super Executive Line, Gambettola, Italy) in each session. All sessions were supervised. Progressive loading levels were monitored continuously and adjusted throughout the entire training period to maintain muscle loading at the intended values.

• During the first 6 training sessions, participants completed 3 sets of 12–15 repetitions at 65–70 % of 1RM. 
• During session 7–12, participants performed 3 sets of 10–12 repetitions at 70–75 % of 1RM, increasing to 4 sets at 70–75 % of 1RM during session 13–18. 
• From session 19 and onwards, participants performed 5 sets with training load progressing from 8–10 repetitions at 75–80 % of 1RM in session 19–27 to 6–8 repetitions at 80–85 % of 1RM in session 28–36 [38]. 

The exercises were performed in a moderately slow, controlled manner with 1–2 s in the concentric- and eccentric phase with a rest of 1–3 min between sets. Exercise compliance (sets, repetitions, and load) was calculated from daily exercise records completed by the instructors at each training session. Participants were informed that a mean attendance of less than 2 training sessions per week resulted in exclusion. All adverse events associated with the training intervention were recorded.

The complex ways in which vitamin D supplements interact with both the levels of the active form of vitamin D 1,25(OH)2D and the binding proteins vitamin D binding protein and serum album has yet not been considered in any of the "vitamin D and gains" studies - epic fail ? (data from Glendenning. 2015)

Vitamin D Binding Protein, Bioavailable Vitamin D & Receptor Polymorphisms - Although it has been known for decades that only 0.1% of the vitamin D in our body and only ~10% of the metabolites in our blood are free, the effects of being bound to its specific binding protein (VDBP) or albumin are still largely unknown. One of the reasons is that studies still rely on unreliable measurements of total vitamin D that are then run through algorithms to elucidate if there's a difference between the effects of free and bound vitamin D (Chun. 2014). This is not only problematic because it assumes that we'd all have the same / similar amounts of vitamin D binding protein, but also because it ignores already established genetic polymorphisms (e.g. inter-racial / whites are more likely to have a low binding affinity than blacks) in how VDBP works and how it affects our health and is affected by supplementing with vitamin D (sign. increases are seen w/ vit D2 or D3 | see Fig.).

A similar negligence can be observed with regard to the role of the vitamin D receptors on its various target organs. While we know that their expression increases with resistance training (no added increase was observed with vitamin D supplementation in the study at hand in contrast to a recent study by Makanae et al. (2015) in rodents), we still have almost no clue how they interact with free and bound vitamin D; and only recently researchers like Jia et al. (2015) have begun to investigate how certain vitamin D receptor polymorphisms (gene types) like the rs739837 gene are associated with increased risk of T2DM. In conjunction with the role of genetic polymorphisms of the binding proteins, the whole system is at the moment, thus way too too complex for us to make predictions on a population or even sub-population levels (like the elderly, men and women at an increased risk of cancer, or patients with autoimmune diseases, or athletes). 

The outcome variables the scientists choose were skeletal muscle hypertrophy, isometric muscle strength, serum vitamin D levels, and a muscle biopsy that was used (a) to analyze several markers of muscle hypertrophy, metabolism & co, as well as (b) to determine whether training or treatment had triggered measurable or even significant changes in the fiber type composition of the subjects.

Figure 2: Serum vitamin D levels at all time-points during the study (I added the markups for the zones to the original figure from Agergaard to make it easier for you to interpret the data).

Of these, I deliberately chose the 25OHD serum levels to start with. Why? Well if you look at the small increase in the young subjects and the still existing gap between their 25OHD (=serum vitamin D) levels and the allegedly "optimal" zone for lower body strength gains (cf. Bischoff-Ferrari. 2006), you may feel reassured that the dosages were too low. This is yet only the case, if the goal was to get the levels into the "magic" 90-100nmol/L of which Bischoff-Ferrari estimated in 2006 that it was optimal for muscle function and health. Whether the effects would have been more pronounced if the subjects had reached this level is yet mere speculation and, if you look at the correlation analysis further down, even highly unlikely (see Figure 5 and respective explanations).

Figure 3: Cross sectional area (CSA), Isometric strength and strength/CSA of Quadriceps muscle. Change in a CSA, b isometric strength and c strength/CSA of quadriceps muscle for young and elderly vitamin-D and placebo groups, respectively. Data shown as mean percentage change from week 0 ± SEM. * different from week 0 (p < 0.05)

Now, as arbitrary as these ranges may be (things like the influence of the vitamin D binding protein levels and genotypes for example, are taken into account, at all | Chun. 2014; Koplin. 2015), we must not and will not ignore the fact that the young, unlike the old(er) subjects, didn't make it into 90-100 nmol/L zone of "magic gains" when we are looking at the data in Figure 3:

• No group effects - The first thing you should realize is that there were no significant inter-group differences and thus no group effects in response to the provision of vitamin D3 vs. placebo. This does imply that neither the increased size gains (A) in the vitamin D group in the young nor the decreased gains in the vitamin D group in the old subjects was statistically significant. The same can be said, albeit in the opposite directions for the strength increases (B) and the relative strength increases (C) in the young subjects.
• Significant time effects - Since subjects in both groups still gained significant amounts of muscle and strength, the one thing the study does confirm is the efficacy of resistance training as strength and mass builder in young and old.
• Significant group effect on relative strength in the elderly - Due to the reversal of the observations compared to the young group (lower size gains + higher strength gains in the older, higher size + lower strength gains in the younger subjects), the relative strength of the older subjects has improved by vitamin D supplementation (p = 0.008, not correctly indicated in Figure 3) - a result that stands in line with previous research like Moreira-Pfrimer et al. (2009) where the provision of 150,000 IU once a month during the first 2 months, followed by 90,000 IU once a month for another 4 months enhanced both, the 25(OH)D levels and the lower limb muscle strength of the > or =60 year old subjects, even in the absence of any regular physical exercise practice.

Now, I would be inclined to ignore the lack of statistical significance for the initially mentioned parameters and jump on the significant increase in the older subjects and the trends we may extrapolate from the rest of the data if it were not for the results of the extra correlation analysis the scientists did. If higher levels of vitamin D3 (90-100nmol/L as they were achieved in the older subjects) could, as Bischoff-Ferrari et al. assume based on observations Guralnik, et al. (1995) and Seeman et al. made in elderly individuals, ameliorate exercise-induced strength gains in the young subjects, there should at least be a correlation between vitamin 25OHD levels and muscle size and strength similar to the one Bischoff-Ferrari et al. report for the 8-foot-walk and sit-to-stand test:

Figure 4: The optimal ranges, Bischoff-Ferrari et al. estimated are based on the above observational data from a 8-foot-walk and sit-to-stand test done in the elderly. That's super reliable and just like you, right? No? Well, that's why I believe those "optimal values" have no relevance for the young and low relevance for the old subjects (Bischoff-Ferrari. 2006)

If the trends you may believe to see in Figure 3 a-c remained trends, because the 25OHD levels didn't rise high enough, the graphs in Figure 5 would look much different: They would firstly show increasing, not no or decreasing slopes and would second of all provide evidence for a practically relevant correlation between the 25OHD levels, the muscle size, strength and relative strength.

Figure 5: Correlation between Quadriceps ΔCSA, ΔIsometric strength, Δstrength/CSA and 25(OH)D (Agergaard. 2015)

In practice, however, the correlation analysis yielded nothing: No correlation between 25OHD and size gains (A), no correlation between 25OHD and strength gains (B), and no correlation between 25OHD and relative strength gains (C). While this does not neglect the possibility that the vitamin D supplement still affected the increase in strength/size ratio of the elderly, the result warrants the conclusion that there was "[n]o additive effect of vitamin-D intake during 12 weeks of resistance training [...] on either whole muscle hypertrophy or muscle strength" (Agergaard. 2015).

So vitamin D supplementation is finally disproven? It is not just the specific study population (unhealthy individuals or athletes may benefit more, men and women may differ (Ko. 2015) etc.) that precludes making overgeneralized conclusions such as "vitamin D supplementation doesn't do anything for your gains". There is more! Firstly, there is the increase in what the scientists call "muscle quality", i.e. the ratio of strength/size increases in the elderly. Now, the data in Figure 5 indicates that this is clearly not a function of the serum 25OHD levels. If that's not the case, however, it could only be mediated by vitamin D3 directly or metabolites that haven't been tested in the study at hand (most prominently active vitamin D, i.e. 1,25-dihydroxycholecalciferol aka calcitriol). If that's the case, age may explain that the older subjects did not see the same changes in fiber type morphology (greater increase in type IIa) and myostatin expression the young ones did.

Figure 6: Significant treatment specific changes in fiber type (%), i.e. increases in fast-twitch type IIa fibers and decreases of the protein synthesis inhibitor myostatin were observed only in younger subjects (Agergaard. 2015).

I highlighted these changes with arrows in Figure 6 and would like to point out that they are the most interesting reason to still supplement w/ vitamin D. Eventually, both effects could affect your gains in the long-term: (I) lower myostatin = higher protein synthesis; (II) more type IIa fibers = higher growth potential. In only 12-weeks, however, newbies don't reach a level where myostatin and/or the fiber composition of their muscle is holding them back, significantly. For athlete and after longer training periods, however, the scientifically proven (albeit in vitro | Garcia. 2013, 2014)  ability of active vitamin D aka calcitriol (and / or vitamin D3 directly - not proven in human muscle) to increase the myogenic differentiation (would explain myofiber changes) and suppress myostatin in human myoblasts could turn out to be game changers.

To find out whether these purported long-term effects exist and/or if similar effects can be seen in non-sedentary adults, like athletes who would benefit the most of reduced myostatin levels and further changes in the muscle architecture, we do yet need more studies. Randomized controlled studies, maybe with different dosing schemes (the ~2,000 IU are not exactly much if we consider potential direct effects) and no more observational bogus on vitamin D | Comment on Facebook!

References:

• Agergaard, Jakob, et al. "Does vitamin-D intake during resistance training improve the skeletal muscle hypertrophic and strength response in young and elderly men?–a randomized controlled trial." Nutrition & metabolism 12.1 (2015): 32.
• Bischoff-Ferrari, Heike A., et al. "Estimation of optimal serum concentrations of 25-hydroxyvitamin D for multiple health outcomes." The American journal of clinical nutrition 84.1 (2006): 18-28.
• Chun, Rene F., et al. "Vitamin D and DBP: the free hormone hypothesis revisited." The Journal of steroid biochemistry and molecular biology 144 (2014): 132-137.
• Garcia, Leah A., et al. "1, 25 (OH) 2 vitamin D 3 enhances myogenic differentiation by modulating the expression of key angiogenic growth factors and angiogenic inhibitors in C 2 C 12 skeletal muscle cells." The Journal of steroid biochemistry and molecular biology 133 (2013): 1-11.
• Garcia, Leah A., et al. "1, 25 (OH) 2vitamin D3 stimulates myogenic differentiation by inhibiting cell proliferation and modulating the expression of promyogenic growth factors and myostatin in C2C12 skeletal muscle cells." Endocrinology 152.8 (2011): 2976-2986.
• Glendenning, Paul, et al. "Calculated free and bioavailable vitamin D metabolite concentrations in vitamin D-deficient hip fracture patients after supplementation with cholecalciferol and ergocalciferol." Bone 56.2 (2013): 271-275.
• Guralnik, Jack M., et al. "Lower-extremity function in persons over the age of 70 years as a predictor of subsequent disability." New England Journal of Medicine 332.9 (1995): 556-562.
• Jia et al. "Vitamin D Receptor Genetic Polymorphism Is Significantly Associated with Risk of Type 2 Diabetes Mellitus in Chinese Han Population." Arch Med Res. (2015): Ahead of print. 
• Ko, Min Jung, et al. "Relation of serum 25-hydroxyvitamin D status with skeletal muscle mass by sex and age group among Korean adults." British Journal of Nutrition (2015): 1-7.
• Koplin, Jennifer J., et al. "Polymorphisms affecting vitamin D–binding protein modify the relationship between serum vitamin D (25 [OH] D 3) and food allergy." Journal of Allergy and Clinical Immunology (2015).
• Makanae, Yuhei, et al. "Acute bout of resistance exercise increases vitamin D receptor protein expression in rat skeletal muscle." Experimental physiology 100.10 (2015): 1168-1176.
• Moreira-Pfrimer, Linda DF, et al. "Treatment of vitamin D deficiency increases lower limb muscle strength in institutionalized older people independently of regular physical activity: a randomized double-blind controlled trial." Annals of Nutrition and Metabolism 54.4 (2009): 291-300.

Kids' Low GL Breakfast Boosts Cognitive Performance 24h Later | Maternal Low Protein Diet Programs High Myostatin, Low Muscularity | Beef Beats Pickled, Not Baked Herring

We all know this is not a healthy breakfast. What we don't or rather didn't know, though, is that you have to test on two consecutive days to find out how unhealthy it actually is for your kids' brains. With Young's study we learned that.

In what? That's probably what you are asking yourself now that you've read that beef beats pickled, but not baked herring, right? Well the answer to this question can be found in my brief summary of the results of Svelander's recent meal-response study. It's, as you may have guessed, the insulin response that sucks for pickled herring. What sucks even more, though, are mothers who are afraid of protein. After all, Liu's latest study shows that they may be setting their kids up to a life as skinny fatness.

When I come to think about it, this may yet be better than giving your kids a high glycemic load breakfast to take to school. After all, Young's latest study shows quite impressively what previous studies may have missed. The ill effects of high GL breakfasts on cognition are neither immediate, nor restricted to the late AM. No, they rather last for 24h+ and maybe even longer.

Learn more about fasting and eating / skipping breakfast at the SuppVersity

Breakfast and Circadian Rhythm

Does Meal Timing Matter?

Breaking the Breakfast Habit

Fasting, Cardio & the Brain

Does the Break- Fast-Myth Break?

Breakfast? (Un?) Biased Review

• Maternal low-protein diet affects myostatin signaling and protein synthesis in offspring's skeletal muscle - Ok, we are talking about swine, but (a) many human beings behave much worse than swine and (b) swine are actually a much better model of human metabolism than rodents and many primates (the real reason they are not the standard model is that they are too large and too long-lived, which means they need too much space, the studies last too long and get much too expensive).
  
  It is thus more than likely that a very similar effect on myostatin and protein synthesis as it was observed by Liu et al. in their latest study in the European Journal of Nutrition where the swine who were fed a protein-deficient diet with only 6% of the energy from protein gave birth to piglets with (a) significantly reduced body weight, (b) significantly reduced muscle weight, (c) extremely reduced relative muscle weight (to body weight) and (d) small muscle with miniscule intramuscular domains.
  

  

  Figure 1: Body weight, muscle weight (LD), myofiber cross sectional are and rel. muscle weight (LD/BW) of piglets born to sows on protein sufficient (12% | SP) and deficient (6% | LP) diets (Liu. 2015).

  While you can see all of that in Figure 1, the reasons for the lack of muscularity can be seen in Figure 2 which tells you that the piglets that were born to mothers on the low protein (LP) diet had significantly increased myostatin (remember myostatin blocks protein synthesis) and accordingly reduced S6K levels.
  
  With the former being the controller and the latter being the executor of protein synthesis, the results of Liu's study leave little room for speculation: A diet that contains only 6% protein - for humans ~20-30g (depending on your baseline intake) - may increase your offspring's risk of becoming under-muscled and skinny fat... what? No, I didn't say "beware vegans" - that was you!
• Herring (pickled & baked) vs. beef, round one - fight! When it comes to the postprandial lipid and insulin responses among healthy, overweight men, the baked herring is said to be the #1 "health choice" - and here's why.
  
  In the corresponding study, scientists from the Chalmers University of Technology, and the Gothenburg University had seventeen healthy, overweight men (mean age 58 years, BMI 26.4–29.5 kg/m2) consume standardized lunches together with 150g of baked herring, pickled herring or baked, minced beef on three occasions in a crossover design. Blood samples were taken just before and up to 7 h after the meal. The postprandial response was measured as serum concentrations of triglycerides (TG), total cholesterol and lipoproteins (LDL, HDL and VLDL), insulin, 25-OH vitamin D (which did not change, by the way) and plasma fatty acid composition.
  

  

  Figure 2: Insulin response of eventeen healthy, overweight men (mean age 58 years, BMI 26.4–29.5 kg/m2) to std. lunches w/ baked or pickled herring, or baked, minced beef (Svelander. 2015). 

  In contrast to the pickled version, where the added sugar messed with the insulin and insulin response (the latter is not shown in Figure 2), both, the baked herring and the baked, minced meat did quite well. Differences in the cholesterol response as you'd expect them did not exist. There was however a small, albeit allegedly statistically significant advantage for the fish(es) in terms of the triglyceride response, which was lower than in the minced beef trial.
  
  Whether that's actually due to the extra omega-3s and whether it is even half as health-relevant as the scientists conclusions that their result "supports previous studies on the beneficial effects of herring on cardiovascular health" (Svelander. 2015) is yet highly questionable, if you asked me.
• Isomaltulose effectively reduced the GL of kids breakfasts and has beneficial effect on their cognitive performance in the late AM and on a 2nd day! If you are following the SuppVersity news on Facebook, you will know that although previous research has associated the glycaemic load (GL) of a meal with cognitive functioning, typically the macro-nutrient composition of the meals has differed, raising a question as to whether the response was to GL or to the energy, nutrients or particular foods consumed.
  
  With the latest study from the University of Wales Swansea, this different. The study that was conducted by Hayley Young, and David Benton contrasted two breakfasts that offered identical levels of energy and macro-nutrients, although they differed in GL, i.e. the insulinogenic effect of the (otherwise identical) carbohydrate content

  "Using a repeated-measures, double-blind design, 75 children aged 5–11 years, from socially deprived backgrounds, attended a school breakfast club and on two occasions, at least a week apart, they consumed a meal sweetened with either isomaltulose (Palatinose™) (GL 31.6) or glucose (GL 59.8). Immediate and delayed verbal memory, spatial memory, sustained attention, reaction times, speed of information processing and mood were assessed 1 and 3 h after eating" (Young. 2015).

  Now, what is interesting and quite revealing with respect to the mixed results of previous investigations is that the nature of the meals did not influence any measure of cognition or mood after an hour; however, after 3 h, children’s memory and mood improved after the lower-GL breakfast.
  

  

  Figure 3: Kids who consumed the low GL meal with isomaltulose vs. glucose on day one had sign. improved information processing (left) and spatial memory (right) on day two (Young. 2015).

  What is even more striking, though, is the second-day effect on the speed at which the kids processed information faster and their spatial memory, which improved significantly when on the day after the kids had consumed the low GL meal. This observation is total news and it clearly suggest that the benefits of low GL meals on cognition are not necessarily acute, but may rather be accumulating.
  
  Overall, the kids were thus able to process information faster and had better spatial memory later in the morning, when they had the low glycemic load (GL) breakfast that was prepared with isomaltulose vs. glucose. The reason why you need any form of "sugar" (isomaltulose is still a sugar) in your kids' breakfast is still beyond me, though.

Is myostatin relevant for mass monsters only, or for normal trainees, as well? You can find the answer to this smart and justifiable question in this SV Classic Article: "More Evidence That Myostatin is an Important Inhibitor of Diet and Exercise Induced Muscle Gains in You & Me" | read more

Bottom line: If I had to pick only one study, I'd pick the Young study as my highlight of this brief nutrition science review and I'd say that it should be obvious why. I mean, come on: Who would have expected that eating a low glycemic load breakfast would yield significant cognitive benefits on the day after you consumed it even if your "day two"-breakfast does not have a low glycemic load?

For me, this is even more exciting than the sad revelation that low protein diets trigger epigenetic changes that are associated with significant increases in myostatin, subsequent decreases in protein synthesis and a significantly reduced muscle weight ... I can thus only hope that no pregnant woman actually believes that eating less than 10% protein would be good for her own health or the health of her unborn child | Comment on Facebook!

References:

• Liu, Xiujuan, et al. "Maternal low-protein diet affects myostatin signaling and protein synthesis in skeletal muscle of offspring piglets at weaning stage." European journal of nutrition (2014): 1-9.
• Svelander, Cecilia, et al. "Postprandial lipid and insulin responses among healthy, overweight men to mixed meals served with baked herring, pickled herring or baked, minced beef." European journal of nutrition (2014): 1-14.
• Young, Hayley, and David Benton. "The effect of using isomaltulose (Palatinose™) to modulate the glycaemic properties of breakfast on the cognitive performance of children." European journal of nutrition (2014): 1-8.

More Evidence That Myostatin is an Important Inhibitor of Diet and Exercise Induced Muscle Gains in You & Me

Is myostatin relevant for mass monsters only, or for normal trainees, as well ?

We all know the freakish images of myostatin negative animals. We all know about the heavily marketed, but scientifically not proven myostatin inhibitors. But do we also know that myostatin is actually a major inhibitor of skeletal muscle growth in the average trainee?

I am not sure, but a recent study from the University of Padova provides further evidence that the muscle hypertrophy break myostatin may in fact be what keeps you from making the same gains you saw, when you first hit the weights (Paoli. 2015).

BFR and Hypoxia Training may decrease myostatin (Laurentino. 2012).

BFR, Cortisol & GH Responses

BFR - Where are we now?

Hypoxia + HIIT = Win?

BFR for Injured Athletes

Strength ⇧ | Size ⇩ w/ BFR

Training & Living in Hypoxia

In said study, Antonio Paoli et al. recruited 18 male volunteers, human movement science undergraduate students (age = 24.9 +/- 5.3 years), who responded to an invitation to participate in the study. The respondents provided written informed consent to participate in the study and were screened for the presence of diseases or conditions that would place them at risk for adverse responses to exercise.

Figure 1: Scheme of experimental design. HP, high protein; NP, normal protein; RT, resistance training (Paoli. 2015)

The subjects were healthy, nonobese, and nonsmokers, and were not taking any medications. Most importantly, however, they had never engaged in regular RT. This gave them the advantage of being strength training virgins and may explain why the supervised exercise sessions which were performed on two nonconsecutive days/week for the first 2 weeks and in 3 nonconsecutive days/week over six months triggered quite significant muscle gains in the subjects who had previously been engaged in 5–6 h/week of various team sports (soccer, volley, and basket).

The IGF-1 Promoting, Myostatin Reducing, Muscle Building Effects of PGC-1 α-4: What It Does and Why Doing Cardio Before Weights Appears to Promote It's Expression | read more.

"The exercises used throughout the program were bench press, latissimus pulldowns, seated rows, shoulder press, biceps hammer curls, and dumbbell lying external rotation. During the first week of training, subjects performed 2 sets of 9–11 repetitions at 75–80% 1RM with 2-min breaks between each set in all exercises except for hammer curl (1.5 min) and dumbbell lying external rotation (1 min). Thereafter, from second to fourth week, the training volume was elevated to three sets. 

At the fifth week the intensity of training was elevated to 80–85% 1RM with three sets of six to eight repetitions. The recovery between each set was 3 min for all exercises except for hammer curl (2 min) and dumbbell lying external rotation (1.5 min). 

From sixth to eighth week the training volume was elevated to four sets. The participants were instructed to perform the repetitions rapidly (1 sec) during the concentric phase and then return the load through the eccentric (lowering) phase at a more slow and controlled speed (1.5/2 sec). The load was adjusted every week according to the actual number." (Paoli. 2015).

In addition to being assigned to identical training protocols, the subjects were randomly assigned to consume either a high or normal protein diet. The participants were put on a fixed-menu plan with either a high (HP) or normal protein (NP) distributed across 5 meals per day. The individual daily caloric need was calculated referring to body composition and adjusted for daily activity. NP and HP diets are isocaloric regarding daily energy needs of subjects while the surplus of calories given by protein supplements were substituted by carbohydrates in diet. Thus

• the subjects in the NP group consumed 0.85 g/kg of body weight protein, while 
• the subjects in the HP group consumed 1.8 g/kg of body weight. 

In that it's important that the increased protein intake was realized via whey protein supplementation that was consumed during the warm-up (10 to 15 min prior to the beginning of training session) and 1 h after the end of the training session in form of a 250 mL of a beverage containing 15–20 g of protein, for a daily amount of 30–40 g or a placebo.

Figure 2: Changes in body composition in the high and low protein group (Paoli. 2015).

Assuming that this is not the first SuppVersity article you read, you will probably not be surprised that replacing carbohydrates with protein to achieve a protein intake of 1.8g/kg vs. 0.85g/kg body weight lead to both increases in lean mass gains and reductions in body fat. This result alone would not warrant a SuppVersity article.

Figure 3: Myostatin increases more in the HP group and it increases hand in hand with IGF-1 (small figure | Paoli. 2015).

What is really interesting, though, is the fact that the necessary increase in protein synthesis in response to the peri-workout ingestion of whey protein lead to likewise significant increases in myostatin, the muscle protein that inhibits further protein synthesis to keep the muscle domain sizes in check (learn more). And there is more: Paoli et al. are the first to demonstrate that IGF-1 and mystatin increase hand in hand (Figure 3). This is particularly interesting, because IGF-1 and its muscle-specific splice-variant MGF are responsible for the formation of new myonuclei from satellite cells and thus a decrease of the domain sizes that keeps the ever-increasing muscle mass functional.

It is thus obvious: The faster you grow - in this case due to the additional supply of whey protein, the faster will the muscular myostatin levels increase. In that, the increase in IGF-1 and the corresponding increase in satellite cell recruitement cannot keep pace with the amount of protein that could be pumped into the muscle if this would not put you at risk of ending up with the same dysfunctional monster muscles as myostatin-negative mice. Monster-muscles that look strong, but are - due to the exuberant domain sizes and lack of myonuclei - dysfunctional.

Domain sizes of EDL and soleus muscle fibers in wild-type control, myostatin negative and IGF1 overexpressing mice (Qaisar. 2012) | learn more.

Against that background it is questionable, whether inhibiting myostatin to a significant degree can actually help you to build big and strong muscles. Rather than a total inhibition of myostatin, people who strive for maximal muscle growth should rather aim for an amelioration of myostatin and a concomitant increase in IGF-1 and MGF to trigger the necessary increases in myonuclei number and domain sizes that keeps the ever-growing muscle functional. But hey, I guess the bros are already doing just that with their sometimes hilarious stacks of potent anabolics | Comment on Facebook!

References:

• Laurentino, Gilberto Candido, et al. "Strength training with blood flow restriction diminishes myostatin gene expression." Med Sci Sports Exerc 44.3 (2012): 406-412.
• Paoli, Antonio, et al. "Protein Supplementation Increases Postexercise Plasma Myostatin Concentration After 8 Weeks of Resistance Training in Young Physically Active Subjects." Journal of medicinal food 18.1 (2015): 137-143.
• Qaisar, Rizwan, et al. "Is functional hypertrophy and specific force coupled with the addition of myonuclei at the single muscle fiber level?." The FASEB Journal 26.3 (2012): 1077-1085.

Exercise Research Update Nov. '14 (2/2): Vibration Training for Athletes, Caffeine Muscle Size & Power, Time to Psyche Up, Myostatin Resp. to Strength & Comb. Training & More

Vibration training is for lazy men & women, only - right? It cannot speed up the adaptation process in athletes, right? And it certainly has no effects on body composition, right? Not exactly, scroll down and find out why.

For those of you who haven't read yesterday's first installment of this research update, I highly suggest you head over now, or after you've read today's follow up on additional vibration training for athletes, caffeine and the effect of muscle size on the strength boosting effects of caffeine, the benefits of and perfect time to psyche up before a sprint event and the muscular myoastatin response to strength, interval and combined training, to make sure you don't miss half this research update.

And if you are not interested in any of these news you may still appreciate the bottom line with a brief review of the latest evidence for the differential or identical effects of strength and hypertrophy training on the acute biochemical and neuromuscular responses justify the classification of strength- and hypertrophy-type resistance exercise.

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• Additional vibration training valid for athletes to develop both strength and hypertrophy of the lower limbs, study shows. The researchers randomly assigned forty-one (32 men and 9 women) recreationally active subjects (21.4 ± 3.0 years old; 172.6 ± 10.9 cm; 70.9 ± 12.3 kg) to either two (G2) or three (G3) vibration training sessions per week for six weeks and measured the changes in maximum isokinetic strength, body composition, and performance in vertical jumps from the beginning to the end of the training cycle (Martinez-Pardo. 2014).
  
  The vibration training stimulus consisted of uniform vertical oscillations. holding an isometric quarter squat position with the feet shoulder-width apart - no fancy exercises or headstands on the plate ;-) After the familiarization week, subjects trained 2 or 3 days per week for 6 weeks (with the exception of the C G) using a vibrating incremental training program that began with 8 sets per session and increasing by 1 set weekly.
  
  

  

  Figure 1: Change in body composition over the course of the 6-week study period (Martinez-Pardo. 2014)

  The frequency of vibration (50 Hz), amplitude (4 mm), time of work (60 seconds), and time of rest (60 seconds) were constant for G2 and G3 groups, the increases in lean mass were not: While the G2 group gained "only" 0.9 ± 1.0 kg, while the subjects in the G3 group who participated  in three weekly vibration training sessions had a whopping 1.5 ± 0.7 kg more lean mass after only 3 sessions per week x 6 weeks = 16 sessions on the vibration plate.
  
  As it was to be expected, neither the total fat mass, nor the fat percentage (measured reliably by DEXA) changed statistically significantly and the bone mineral content, and bone mineral density of the men and women in both groups didn't change at all (previous studies show that vibration training can increase bone density or at least reduce the bone loss in people who are at risk of osteoporosis | de Zepetnek. 2009). 
• Caffeine & muscle power - Larger muscle groups benefit more, study shows. Right from the labs of the University of Edinburgh comes the news that 6 mg/kg caffeine (CAF) increase the isokinetic peak torque of the knee extensors, ankle plantar flexors, elbow flexors and wrist flexors proportionally to the respective size of the muscle group.
  

  

  Figure 2: Relative increase in isokinetic peak torque values of the 4 muscle groups for the CAF vs. placebo treatments at an angular velocity of 60°/s (Timmins. 2014)

  More specifically, statistical analyses revealed a significant increase in isokinetic peak torque from PLA to CAF (p = 0.011) for all, but significant difference in isokinetic peak torque between muscle groups (p < 0.001).
  
  As the scientists point out, "[t]his research may be useful for competitive and recreational athletes aiming to increase strength-power performance," because they now know that (a) caffeine works and (b) that it will work better for larger vs. smaller muscle groups.

• 

  Figure 3: Mean change in performance for each condition and time interval. A) Overall 30-m sprint time. B) Acceleration phase of the sprint, i.e. 0- to 10-m lap time (Hammoudi-Nassib. 2014)

  Is it time to "psyche up", already? Scientists investigate relationship between time interval between psyching up and sprint performance. In their latest study researchers from the Tunisian Research Laboratory Sports Performance Optimization National Center of Medicine and Science in Sports (CNMSS) found that imagery techniques were specifically effective in enhancing the performance on the phase of acceleration (0–10 m) and on the overall sprint (0–30 m) when they were used immediately before performance and at 1- and 2-minute intervals.
  
  When the subjects were asked to use the same technique 3- and 5-minutes before the sprints, though, no effect was observed. As the researchers point out, their "findings support the hypothesis that the potential effect of the PU [psyching up] strategy on performance vanishes over time." (Hammoudi-Nassib. 2014)
• Skeletal muscle myostatin response is identical for strength training (ST), interval training (IT) and concurrent training (CT), study finds. Researchers from the University of São Paulo tested the differential effects of the previously mentioned training regimen in thirty-seven physically active men over the course of an 8-week training period and found that ...
  

  • 

    Figure 3: No sign. difference in myostatin response to training (de Souza. 2014)

    Type IIa and type I muscle fiber CSA increased from pre- to posttest only in the ST group (17.08 and 17.9%, respectively). 
  • The SMAD-7 gene expression significantly increased at the posttest in the ST (53.9%) and CT groups (39.3%). 
  • The MSTN and its regulatory genes ActIIb, FLST-3, FOXO-3a, and GASP-1 mRNA levels remained unchanged across time and groups. 
  Moroever, the one repetition maximum increased from pre- to posttest in both the ST and CT groups to a similar extent (ST = 18.5%; CT = 17.6%).
  
  In spite of the fact that the scientist say that their "findings are suggestive that MSTN and their regulatory genes at transcript level cannot differentiate muscle fiber CSA responses between CT and ST regimens in humans" (de Souza), one could still speculate that the non-significantly lower myostatin levels in the ST-only group (see Figure 3) may already have been enough to cause the small, but significant difference in typeIIa and type I fiber CSA increase from pre- to postttest the researchers observed.

Photo from FighterDiet.com -- Powerlifting training can yield similar results as classic hypertrophy training. Is this because the acute biochemical and neuromuscular responses do not differ | learn more 

Before I call it a day, I would still like to draw your attention to yet another study that was published in the latest issue of the Journal of Strength and Conditioning Research, one that tried to answer the question, whether "the acute biochemical and neuromuscular responses justify the classification of strength- and hypertrophy-type resistance exercise" (Nicholson. 2014) and found that the only difference between strength and hypertrophy type workouts - despite their significant different intensities, volumes, and rest times (STR: 4 × 6 repetitions, 85% 1 repetition maximum [1RM], 5-minute rest periods vs. HYP: 4 × 10 repetitions, 70% 1RM, 90-second rest periods) - was observable in the acid-base response to the workout. Accordingly, Nicholson et al. conclude that "practitioners to look beyond the classification of RE workouts when aiming to elicit specific physiological responses" (Nicholson. 2014). Maybe that's also why powerlifting- and hypertrophy-like workouts have been shown to yield very similar outcomes in recent studies (learn more)?

References:

• de Souza et al. "Effects of Concurrent Strength and Endurance Training on Genes Related to Myostatin Signaling Pathway and Muscle Fiber Responses." Journal of Strength and Conditioning Research 28.11 (2014): 3215–3223.
• de Zepetnek, JO Totosy, Lora M. Giangregorio, and B. Catharine Craven. "Whole-body vibration as potential intervention for people with low bone mineral density and osteoporosis: a review." J Rehabil Res Dev 46.4 (2009): 529-542.
• Hammoudi-Nassib et al. "Time Interval Moderates the Relationship Between Psyching-up and Actual Sprint Performance." Journal of Strength and Conditioning Research 28.11 (2014): 3245–3254.
• Martinez-Pardo et al. "Effect of a Whole-Body Vibration Training Modifying the Training Frequency of Workouts per Week in Active Adults." Journal of Strength & Conditioning 28.11 (2014):3255–3263.
• Nicholson, et al. "Do the Acute Biochemical and Neuromuscular Responses Justify the Classification of Strength- and Hypertrophy-Type Resistance Exercise?"  Journal of Strength & Conditioning 28.11 (2014): 3188–3199.
• Timmins & Saunders. "Effect of Caffeine Ingestion on Maximal Voluntary Contraction Strength in Upper- and Lower-Body Muscle Groups." Journal of Strength & Conditioning 28.11 (2014):3239–3244

Myostatin Limits Muscle Hypertrophy in Young, Physically Active Resistance Trainees on High, but Not Normal Protein Diet - Irrelevant Outlier or Crucial Revelation for Trainees?

Who says, resistance training and high protein diets make you bulky? The study at hand suggest they don't because after a couple of weeks your body will pull the myostatin break | img (c) fighterdiet.com

You're training like mad and consuming a ton of protein everyday and still don't see the results you deserve? Maybe increased myostatin levels are holding you back!?

While previous studies mostly suggested that the role of myostatin in the normal (muscle) growth response to exercise may have been overestimated, a recent study from the University of Padova,  the Italian Medicine and Fitness Federation, Euganea Medica, and the University of Palermo. Brings the "muscle-growth break" (high myostatin = slow muscle gains) back onto our radar. And that not just because researchers from said institutions observed a significant increase in myostatin in response to chronic resistance training, but rather because this response appears to have been triggered by high(er) protein intakes.

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If you have been reading SuppVersity articles for quite a while now, you may remember my previous post about how "Chronic Resistance Training Reduces the Anabolic Signaling in Response to Exercise - 12 Days of Detraining Restore It" (read more). The corresponding study by Ogasawara et al. (2013) was yet conducted on rodents. Therefore, the applicability of the results remains at least questionable.

In a more recent study with human subjects, Antonio Paoli and colleagues from Italy did yet observe a similar, but not identical effect. The researchers aim was to "investigate the influence of 2 months of resistance training (RT) and diets with different protein contents on plasma myostatin (MSTN), interleukin 1 beta (IL-1β), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and insulin-like growth factor 1 (IGF-1).

Does an increase in protein intake increase myostatin, as well?

To this ends, they recruited 18 healthy, young, physically active volunteers who were then randomly divided in two groups; A high protein (HP) and normal protein (NP) groups. The diets contained 1.8 and 0.85 g of protein/kg body weight per day for the HP and NP diet, respectively.

In addition to the dietary intervention, all subjects were subjected to the same 8 weeks of standardized progressive resistance training. MSTN, IGF-1, IL-1β, IL-6, and TNF-α were analyzed before and after the first and the last training sessions. In addition, Paoli et al. measured the lean body mass, muscle mass, upper-limb muscle area, and strength.

Figure 1: Much to the surprise of the researchers, the muscle gains were identical, but the msucle gain reducing myostatin increase was significant only in the high protein group (Paoli. 2014)

Somewhat to the scientists surprise the plasma MSTN showed a significant increase (P<.001) after the last training in the HP group compared to both the normal protein (NP) group and the starting values. Surprisingly, these increases occurred in the absence of differences in IL-1β, IL-6, TNF-α, and strength and muscle mass or muscle area.

Protein blunts the exercise induced decrease in myostatin, but it increases the alleged myostatin blocker FLRG (Hulmi. 2008) - Result? A null or maybe even beneficial effect?

This is not an outlier study! Bad news, bros You cannot discuss the findings of the study at hand away. Previous studies by Hulmi (2008) found that the decrease in myostatin that would usually occur in response to resistance training in older male trainees was blunted, when the resistance training session was followed by the ingestion of 15g of whey protein. Needless to say that this does not necessarily mean that you'd gain less. In fact, the concomitant increase in folistatin related gene expression (FLRG), a gene which is thought of regulator off the myostatin inhibitor folistatin (Hill. 2002), may more then compensate the slight increase in myostatin (see Figure on the left) in the first 48h after a workout. If that's the same in the long run, will have to be tested in future studies.

If the muscle mass / area had been increased as well, it would have been easy to interpret the increase in myostatin as a reaction to an increase in muscle cell size and a corresponding increase in domain sizes. The way it is, though, it's difficult to explain the increase in myostatin and its correlate IGF-1 (correlate in this study, not in general).

Is this just a matter of domain sizes?

Figure 2: Domain sizes of EDL and soleus muscle fibers in wild-type control, myostatin negative and IGF1 over-expressing mice (data based on Qaisar. 2011)

As you will remember from previous articles, the latter would require the recruitment of additional muscle satellite cells that would form new myonuclei and thus help normalize the domain sizes and myostatin levels.

Without myostatin, the domain sizes would keep increasing and the muscle would become as huge, but dysfunctional as it does in myostatin negative mice (see Figure 2, red | not the similar increase in domain size in IGF-1(+) mice which underlines the role both myostatin and IGF-1 play when it comes to controlling domain sizes and facilitating "Getting Big Beyond Temporary Physiological Limits" | learn more)

The way it is, the observations Paoli et al. made in their most recent study remain, as the authors themselves call it "paradoxical" and could in fact "explain the substantial overlapping of MM [muscle mass] increases in the two groups", no one of you would have expected, right? Well, it's a pitty we don't have data on the level of follistatin related gene expression as it was measured in the Hulmi study (see red box) - if that did not increase, or only to a small extend, it's actually no wonder, both groups gained the same amount of muscle mass.

How intense is "intense enough"? The training program Roth reused in their 2003 study and which reduced the myostatin expression sign. consisted of five sets of high-volume (55 total repetitions), heavy-resistive exercise performed 3 days/wk. The resistance for each set was based on the subject’s 5RM. After performing a first set of five repetitions at 50% of the original 1RM for a warm-up, the subject performed a second set of five repetitions at the 5RM resistance after a 30-s rest period. The third set consisted of 10 repetitions, with the first four or five repetitions at the current 5RM value, then the resistance was lowered just enough to complete one or two more repetitions before the subject reached fatigue. The process was repeated until a total of 10, 15, and 20 repetitions were completed for the third, fourth, and fifth sets, respectively. The third, fourth, and fifth sets were preceded by rest periods lasting a minimum of 90, 150, and 180 s, respectively. This protocol demanded a near-maximal effort on every repetition throughout each set.

Do we need myostatin blockers to maximize our gains? As far as I know, no scientifically proven myostatin inhibitor is yet available as an OTC supplement. Luckily, previous research by Roth (2003) and Willoughby (2004) suggests that these products may not even be necessary. In 2003 Roth et al. write in a "short communication" (something similar to a "mini paper") that really heavy resistance training with maximal effort on each set can (at least temporarily) reduce the myostatin levels (see box to the right for information on the exact protocol) - an effect that is unfortunately reduced with aging and almost non-existant in aging women (old men -37%, old women -11%, young men -56%, young women -46% | Kim. 2005), but could be buffered by concomitant increases in folistatin-related gene (FLRG) expression, as it was observed by Willoughby in his 2004 study.

Figure 3: Serum folistatin related gene expression in response to 12 week high intensity resistance training vs. control (Willoughby. 2004)

The key to actually making the gains you could make due to the increase in protein availability, could thus simply be to train harder to either facilitate greater reductions in myostatin or promote long-term increases in its "buffer" FLRG, as they were observed by Willoughby (see Figure 3).

In the long run, this does yet entail the risk of severe overtraining, which should remind you of the periodization techniques and the interplay of phases of maximal and sub-maximal exercise intensity in 4-6 week cycles. You have no idea how that works? Well, I suggest you take a look at the overview of previous SuppVersity articles on periodization - specifically this one: "Periodization Techniques Revisited: Improved Strength & Size Gains W/ 12-Week Undulatory vs. Linear Periodization" | Comment on Facebook.

References:

• Hill, Jennifer J., et al. "The myostatin propeptide and the follistatin-related gene are inhibitory binding proteins of myostatin in normal serum." Journal of Biological Chemistry 277.43 (2002): 40735-40741.
• Hulmi, Juha J., et al. "The effects of whey protein on myostatin and cell cycle-related gene expression responses to a single heavy resistance exercise bout in trained older men." European journal of applied physiology 102.2 (2008): 205-213.
• Paoli, et al. "Protein Supplementation Increases Postexercise Plasma Myostatin Concentration After 8 Weeks of Resistance Training in Young Physically Active Subjects." J Med Food. Aug 18 (2014). Epub ahead of print.
• Qaisar, Rizwan, et al. "Is functional hypertrophy and specific force coupled with the addition of myonuclei at the single muscle fiber level?." The FASEB Journal 26.3 (2012): 1077-1085.
• Roth, Stephen M., et al. "Ultrastructural muscle damage in young vs. older men after high-volume, heavy-resistance strength training." Journal of Applied Physiology 86.6 (1999): 1833-1840.
• Roth, Stephen M., et al. "Myostatin gene expression is reduced in humans with heavy-resistance strength training: a brief communication." Experimental Biology and Medicine 228.6 (2003): 706-709.
• Willoughby, Darryn S. "Effects of heavy resistance training on myostatin mRNA and protein expression." Medicine and science in sports and exercise 36.4 (2004): 574-582.