A Low Fat Advantage For Alternate Day Fasting? While the Improvements in Body Composition Are Virtually Identical, Only the 25% Fat Diet Will Improve Arterial Blood Flow

If I know anything for sure, it is that the reason your midsection does not look like this, but rather like the one of Melissa McCarthy is not a result of the fact that your diet contains 24% instead of 48% fat.

Outrageous, right? What? Well, the title of this post. I mean even the use of the term "low fat advantage" is probably going to piss a couple of people off, these days. So, please low carb crusaders, don't kill the messenger, it was not my idea to put 32 obese subjects (mean age 43y) onto alternative day fasting regimen that provided either 45%  (ADF-HF) or just 25% (ADF-LF) of the energy in form of fat (25% fat) and to observe what happens to their almost 50% fat (46kg of pure fat on 96kg of total body weight) bodies during a 2-week baseline weight maintenance period and an 8-week alternative day fasting weight loss period, in the course of which all foods were provided by the research team at the Department of Kinesiology and Nutrition of the University of Illinois at Chicago (Klempel. 2013).

"Still outrageous, almost blaspheme!",...

... well, so were the results: There were no differences in body weight or body fat loss and as Klempel, Kroeger, Norkeviciute et al. point out "improvements in FMD [brachial artery flow mediated dilation] with ADF [alternate day fasting] may only occur with LF diets and not with HF diets" (Klempel. 2013). Or put simply - as a really obese individual, you would not really have to worry about your carb/fat ratio, if getting lean was all you were concerned about. If you want to improve your heart health, though, it appears prudent to follow a relatively low fat intake - keep in mind 25% is still more than enough to get all the fat you need for your endocrine system to keep functioning.

"Gimme the details on the study protocol!"

So, now that you've got the basic message, let's take a look at how these results actually came about: The subjects had been recruited from the Chicago area based on the following inclusion criteria: Female, age 25–65 years, body mass index between 30 and 39.9 kg m², stable weight for at least three month before the intervention, nondiabetic (this does not mean they were not insulin resistant, but it means their pancreas was not already damaged), no history of cardiovascular disease, sedentary or lightly active for at least 3 months before the beginning of the study, non-smoker, and not taking weight loss, lipid-lowering, or glucose-lowering medications. There were N = 17 an N = 18 subjects in the high and low fat groups respectively (randomized) and the total duration of the study was 8 weeks.

• 

  As usual, there are arguments (though not from fasting studies) on both sides of the divide; studies where people are only given lose instructions and no foods, do yet often produce very questionable results (learn more).

  as mentioned before, all food was provided throughout the 10-week trial to all subjects; the diets were provided as a 3-day rotating menu consisting of typical American foods; participants were requested to eat only the foods provided and to bring back any leftover foods to be weighed and recorded
• moreover, subjects were instructed to keep track of all food items consumed using a ‘Food checklist’, and to report any extra food item consumed using an ‘Extra food log’. If the log indicated that the subject ate extra food items (totaling 450 kcal) on a feed or fast day, that day was labeled as ‘not adherent’.
• hunger, satisfaction and fullness were assessed using a questionnaire with a validated visual analog scale on each fast day; the form was completed in the evening, approximately 5 min before going to bed
• participants had to wear a pedometer each day throughout the 10-week trial, to record the free-living physical activity 
• during the active weight loss pahse (weeks 3-10) subjects consumed 25% of their energy needs on the fast day (24-h period) and 125% of their energy needs on the feed day (24-h period)
• feed/ fast days began at midnight each day
• fast day meals were consumed between 12pm and 2pm

• 

  Most formulas that are used to calculate your energetic requirements are about as "accurate" as the reading from the globe in Anelina,... ah Lara's hand (learn why)

  the same macronutrient composition was used during the weight loss and weight maintenance periods for each group, with...
• ADF-HF (45% fat, 40% carbohydrate and 15% protein),
• ADF-LF (25% fat, 60% carbohydrate and 15% protein)
• the fats in the diets consisted of
• ADF-HF (14% saturated fat, 20% monouns. fat, 11% polyuns. fat and 0% trans fat) and 
• ADFLF (6% saturated fat, 13% monouns. fat, 6% polyuns. fat and, 0% trans fat)
• the energy requirements were calculated at the beginning of the study and at the beginning of the weight loss intervention using the Mifflin–St Jeor equation, using an "activity factor" of 1.2 (=sedentary; learn more about the equation)  

The body weight measurements were taken weekly, and fat as well as fat-free mass (FFM) were reliably assessed by dual-energy X-ray absorptiometry at baseline and week 8, while the waist circumference was simply measured with a tape to the nearest 0.1 cm, midway between the lower costal margin and super iliac crest during a period of expiration.

"Ok, that's enough, what about the results"

Wow... now, that you know all the important and less important details about the methods, it's about time to eventually look at the actual outcomes of the study:

Figure 1: Changes in body composition (left) and adipokine levels (right) from week 0-8 (Klempel. 2013)

It does not take a rocket scientists to see that the inter-group differences were marginal and statistically non-significant. What's also interesting, is the fact that the weight of the high fat diet group decreased significantly more during the baseline weight maintenance period (2.1±0.4 kg vs. 1.7±0.4 kg). Funnily, this was a period in which all subjects followed the same low(er) fat diets consuming what the scientists calculated would be their maintenance intake (note; this does tell you something about how much those guys usually ate and "why they were fat" to begin with - the girls ate too much).

Low fat and satiety, how does this go together?

What is quite astonishing - and this goes against everything you'll hear on the Internet about the downsides of "low fat" and the benefits of "high fat diets" - is that the subjects in the low fat group, were slightly less hungry (25 vs. 24), experienced a significantly larger increase in satifsaction (+26 vs. +1) and fullness (+20 vs. -17) and did not decrease their daily activity level to the same extent the high fat dieters did (-157 vs. -644).

Looking at the absolute levels, not the differences from baseline, the image is yet less clear. In absolute terms, the satisfaction and fullness levels, of which the scientists point out that it "started out low in the LF group, but gradually increased over 10 weeks" (Klempel. 2013).

Still, it were the participants in the low fat group who saw greater improvements in adiponectin (51±7% vs. 43±7%), a less pronounced drop in leptin (30±3% vs. 32±5%) and a minimally greater improvement in resistin (27±4% vs 23±5%; cf. figure 1) levels, none of which was found to correlate with fat mass loss and can thus expected to be diet and not fat loss specific. Furthermore, it is, as the scientists point out, well possible that it is at least partly due to these changes in adipokine expression that the low fat group saw improvements, the high fat group further deterioration in brachial artery flow mediated dilation:

Insulin is a natural NO booster: You may remember having read about it on the SuppVersity Facebook wall. Insulin has a direct effect on the NO induced widening of the arteries - as long as the cells in the arterial wall, are not already insulin resistant, that is (cf. Rajapakse. 2013). Since intermittent / alternate day fasting will help restore this insulin sensitivity, the increase in FMD could well be "insulin-dependent", as well.

The role that leptin and resistin have in mediating FMD most likely involves changes in the production of NO. More specifically, leptin and resistin blunt the production of NO, which likely occurs through the stimulation of reactive oxygen species that scavenge NO and impair endothelial NO synthase function. As concentrations of these adipokines were reduced in the present trial, we would assume that there would be less leptin and resistin in the circulation to inhibit NO. This would lead to a higher production of NO, resulting in an enhancement in endothelium-dependent vasodilation. The reason why these decreases in leptin and resistin did not contribute to increases in FMD is unclear. However, it is possible that greater decreases in leptin (450%) would be necessary to improve FMD." (Klempel. 2013)

As mentioned before, the other differences are actually not worth discussing and if it was not for the statistically significant improvement in the flow-mediated dilation of the brachial-artery (+2.1%), which was absent in the high fat group (-1.8% reduction in FMD, you would be hard pressed to find arguments in favor of any of the diets.

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The evidence for or against low vs. high fat diets is far from being conclusive. I guess that's also why the "war" between the proponents of one or the other way of eating is fought with with no holds barred.  There is still much to be learned and many results, such as the non-fattening effects of low fat diets on a caloric surplus go against the unique and all-across the board, one size fits it all benefits of low carbing (learn more)

So what's the verdict then and are there implications for true intermittent fasting? Well, first of all the differences are not large enough to warrant the scientists' implicit assertion that "only" the low fat alternative fast was beneficial. On the other hand, the results of the study at hand clearly disprove the current Internet paradigm that a higher fat and lower carbohydrate intake would yield more pronounced fat loss and greater satiety not only, but especially, when the diet involves long phases of "not eating" aka fasting.

That being said, it is not warranted to draw any reliable conclusions wrt to a "lean gains" type of intermittent fasting in athletic individuals based on the study at hand. In my humble opinion, there is yet no good reason that would speak in favor of going low carb either. This is particularly true if you are adding a reasonable workout routine that goes beyond doing a one-rep max effort per day to exponentiation the results of the diet. In that case, you are better off providing your muscles and liver with glucose directly than having the latter produce it from protein (first) and fat (second), which is what will necessarily happen unless you are eating so little protein that you actually make it into full ketosis.

References:

• Klempel MC, Kroeger CM, Norkeviciute E, Goslawski M, Phillips SA, Varady KA. Benefit of a low-fat over high-fat diet on vascular health during alternate day fasting. Nutr Diabetes. 2013 May 27;3:e71.
• Rajapakse NW, Chong AL, Zhang WZ, Kaye DM. Insulin-mediated activation of the L-arginine nitric oxide pathway in man, and its impairment in diabetes. PLoS One. 2013 May 2;8(5):e61840.

Blood Flow Restriction, Where Are We? "Don't Hold Your Breath", the Valsalva Maneuver Revisited. Ageless Growth, It's Never Too Late to Start. Plus: EMS as Recovery Tool & HIIT to Heal a Scarred Heart After Myocardial Infarctions

I guess it is a cultural thing that there is apparently a lot more of persuading to be done in the US and Europe to familiarize trainees with (a) the idea of limiting the blood supply to their musculature and (b) the notion that heavy weights are not all that counts.

After the huge success of the SuppVersity Exercise Science Week (read all posts), I did actually intend to put a greater emphasis on training related news in the future. Unfortunately, the number of pertinent papers that don't look at the benefits obese post-menopausal women can derive from walking on a treadmill in the fat burning zone is very limited (Please don't misunderstand this as an offense against the obese women. I anything it's meant as an offense against "experts" still advising those women to do just that). If you look closely enough, there are still a couple of newsworthy papers that have been published within the last weeks... and let's be honest, in the end it does not really matter, if they are from last week, as long as the information they provide is "news" in terms of not being part of common knowledge, yet - right?

Kaatsu - a review: Blood flow restriction research still work-in-progress

(Pope. 2013) -- Pope, Wilardson and Schoenfield have recently published an ahead-of-print paper that offers a very comprehensive overview of the current scientific perspective on training with cuffs (aka Kaatsu training). As the authors point out, the most intriguing aspect of blood flow restricted training (BFR) is that it is totally juxtaposed with the "traditional [strength training] paradigm, which suggests that lifting only higher intensity loads increases" muscle strength and size.

Figure 1: Concurrent lactate & GH increases support the metabolic accumulation hypothesis, one of the most popular explanations for the effects of BFR  (Inagaki. 2011).

One of the most commonly head explanations of the unexpected efficacy of blood flow restricted strength training at low intensities relates to the accumulation of what you could jovially call "metabolic waste" in the trained muscle. The results of a 2011 EMS study by Inagaki et al. (see figure 1), for example; suggest that the accumulation of lactate in the cuffed muscle went hand in hand with a +200% increase in growth hormone (GH) compared to the control condition. 

As Pope et al. rightly point out, these results do yet conflict with previous findings by Reeves et al. who observed similar increases in GH in trainees who wore a cuff while they were doing biceps curls at 30% of the 1-RM, despite identical lactate levels in the cuffed an not-cuffed condition (Reeves. 2006). Accordingly, alternative or rather synergistic effects such as an increase in reactive hyperemia (excess of blood) have been brought forward to explain the growth response to BFR.

I am not going to reiterate the whole review here, but still want to point out a couple of other interesting points, the Pope, Willardson and Schoenfield make. There would be, for example the increase in type II (fast, glycolytic) muscle fiber recruitment that was observed in some, yet not all studies, an increase phosphorylation of the protein synthesis gauge S6K1 (likewise a type II fiber dominant effect) and the accumulating evidence that BFR may "enhance recruitment of higher threshold motor units". In the end, the latter means that you will see similar activation patterns as you would expect them in "classic" heavy duty resistance training with comparably light loads and a cuff.

Will BFR soon become a common training technique?

"Chicken legs no more!" In a previous study even walking on a treadmill provided a growth stimulus, when the legs were cuffed before the participants hopped on the torture machine (learn more).

Yet while the implication (=similar results) appear obvious, Pope et al. are correct, when they point out that the "precise relationship between BFR and muscle recruitment still has to be elucidated" before definite conclusions wrt to the fundamental mechanism and their relation to the well-established metabolic and endocrine and paracrine responses, which do in fact share some, yet not all of the characteristics of "classic" resistance training (e.g. no increase in testosterone in response to BFR training; cf. Reeves. 2006; Fujita. 2007; Abe. 2012) can be made.

Once we have gained a better understanding of the processes that take place during and after BFR resistance training, researchers will probably also be able to provide more concrete advice how training with reduced blood flow can be successfully incorporated into the resistance training regimen of trainees on both ends of the performance continuum that ranges from the cancer cachetic patient to the elite level athlete.

Until then and in the absence of someone who's actually knowing what he/she to "cuff me up", I for my part will stick to traditional high intensity weight and interval training and would suggest that you do the same ;-)

"Deadlift, bench and squat, but God forbid: Never hold your breath!" - True or false?

(Hacket. 2012) -- I guess you will have heard about the fallacy of holding your breath while you bench squat and deadlift. It's one of those things every "I got 2h of instructions, now I am a trainer"-expert will tell his clients: "Don't hold your breath... breath!" On the other hand you will hear some of the "big dudes" tell you that you simply cannot lift weights as heavy as they do, if you don't resort to the Valsalva maneuver (VM) which is actually pretty much what most of us are doing, when we are "holding our breath", when lifting. If you carefully observe yourself, when you try to deadlift 80%+ of your 1-RM max you will realize that you do in fact hold your breath, but not like an apnoe diver would do it, on the contrary actually it's like breathing out yet with having your airways closed up.

So why are we doing bullsh*t like that 100% unvoluntarily? Well, the opponents of "holding your breath" will tell you that the pressure that's building up in your abdomen will stabilize your spine and protect you from injury. Against that background it seems only logical that we are naturally programmed to perform such a maneuver whenever we have to lift a heavy object from the ground or free ourselves from a tree that's lying right across our chest by benching it away ;-)

Even  when you are training for strength, heavy weights are not everything. A study I covered back in 2011 here at the SuppVersity showed - allegedly to my own surprise - that reducing rest times from week to week is another way to make progress and gain more mass and strength - particularly in the legs (read more)

Unfortunately, we all know that not all the things we are programmed to do - e.g. eating as much sugar as humanly (in the literal sense) possible, whenever we hit onto a honey-pot - is not necessarily conducive to our health. The existing literature on the matter appears to confirm this notion. It does however also tell us that the majority of healthy resistance trainees do not just get away pretty well when they follow their instincts and perform the Valsalva maneuver, but also achieve the desired increase in spine stability.

How effective this type of all-natural spine protection actually is, has yet never been fully elucidated. The same goes for the performance increases which are, as the scientists point out, "likely", but not adequately quantified in well-controlled studies. That there is a non-negligibly increased risk involved, especially for people with pre-existing cerebrovascular disease, cardiovascular disease and hernias, on the other hand, is non-debatable.

Against that background and in view of the fact that the hemodynamic response (=increase in blood pressure, etc.) decreases over years of training, the authors conclude that the deliberate use of the Valsalva maneuver for brief time-periods (<3s) should remain a prerogative of the more experienced trainees. 

Electrical muscle stimulation (EMS) as a recover tool

SuppVersity veterans know: Recovery begins before you even hit the gym. "Pre-covery" would in fact be an appropriate term for the scientifically proven benefits of taking a hot bath 2 days before a particular strenuous workout or competition. Sounds hilarious? Well, if that's what you think, you better go back and read up on the results of the 2012 study by Touchberry et al., then.

(Kibisa. 2013) -- Ever since the huge disappointments with EMS ab-trainers, the electro-myostimulation is pretty much depreciated by the average trainee. If you still got one of those belts lying around (don't be ashamed ;-) you may want to wrap it around your calves, instead of your abs to use it as a recovery tool similar to the obviously way more sophisticated EMS devices the scientists from the Lithuania Kaunas College used in their latest study.

Kibisa et al. had recruited a group of 19 long-distance runners who had then been randomize to two groups who performed either their regular post-training routine or were attached to the said EMS device in order to apply what you may call a "post-workout recovery stimulus". Interestingly this treatment lead to significant increases in a subsequent maximal voluntary contraction (MVC) and work capacity (WC) tests, as well as profound decreases in in the 72h post muscle soreness.

As you probably would have guessed, the scientists ascribe these benefits to an "improved blood flow in the stimulated muscles and an increased venous blood pump". This however is nothing you could not achieve by an extended cool down, as well so that the study at hand won't qualify as an excuse to go and buy an EMS belt for your abs from the shopping channel ;-)

HIIT after infarction reduces scarring of heart tissue

In the unfortunate case you missed the Making HIIT a HIT! Series I highly suggest .you go back and learn about the fundamental and not so fundamental rules of how to HIIT it right. Part I comprises a brief research overview to give you an idea of what you can expect from HIIT workouts. Part II provides some theoretical considerations and a comprehensive list of 10 rules of thumbs to follow, in order to make HIIT a HIT ;-)

(Godfrey. 2013) -- The longstanding paradigm that rest facilitates recovery in the really sick is crumbling. Against that background it's not totally surprising to see that researchers from the School of Sport and Education at the Brunel University in the UK dared publishing a case-report dealing with a 50-year old post-myocardial infarction patient, who participated in 60 weeks of increasingly intense (obviously according to what a post-myocardial infarction patient can tolerate) high-intensity aerobic interval exercise.

The man who had sustained an idiopathic acute myocardial infarction had been diagnosed with 16% myocardial scar tissue early after the event saw successive improvement in the physiology of his hard, with an MRI-confirmed decrease in myocardial scar tissue. As the scientists point out, he is thus living proof for the "high efficacy and low risk" of high intensity aerobic interval training as a means not just to prevent future cardiac complications, but even to reverse existing damage.

Resistance training works *fullstop* - Regardless of age

(Mero. 2013) -- In the March issue of the European Journal of Applied Physiology Mero et al. report that their 21-week progressive resistance training regimen (two full-body workouts per week classic progression from 15 reps at 40-60% to 5-8 reps at 70-80%) yielded significant strength and size gains in old and young previously untrained subjects.

Figure 2: Changes in muscle cross sectional area and strength at the end of the 21-week study period (Mero. 203)

What's certainly surprising is the fact that there were no differences in terms of strength gains at the end of the study period between the young and old trainees. This is particularly interesting, because the "old chaps" obviously caught up, in the 2nd (=higher intensity) phase of the study. After 10.5 weeks, the young trainees had had a statistically significant advantage as far as the concentric strength was concerned. This advantage did yet melt away in the subsequent weeks.

Remember the article on the usefulness of HMB for the older trainees? With its anti-catabolic effect it would leave more of the scarce satellite cells for growth. Plus: It appears to have anti-obesity effects as well (read more)

In a way the presence of strength in the absence of size gains fits in nicely with the high myostatin expression in the older trainees which increased by >50% in the course of the study (read more about the role of myostatin building muscle) and the even more pronounced increase in myogenin, which suggest that the recruitment of satellite cells is slow / non-function in older trainees and further growth would hamper the function of the muscle cells (which is what myostatin is supposed to prevent learn more).

That two training sessions per week did yield statistically significant increases in muscle size and strength and that despite suboptimal energy and protein intake in the older individuals (<1g/kg body weight protein per day for many of the older subjects vs. 1.5g/kg of protein in the young guys; overall significantly lower energy intake than the young guys) is still impressive and goes to show you that it's never to late for you to start lifting weight.

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It's never too late! I could hardly imagine a better bottom line to this short potpourri of recent studies and it's unfortunate that for way too many of our fellow men, even an eye-opener like a heart attack is not enough to divert from the well-worn path of a sedentary life... ok, that was more than enough finger wagging for today. After all, the fact that you've found your way to the SuppVersity is evidence tells me that your path probably ain't going to end in the emergency room.

Well, unless you are a post-menopausal woman taking who's determined to take high dose folate supplements for the next 6+ years. In that case, you may well end up in the ER when the tumor in your colon you've been cultivating over the past 72 months bursts. You have now idea, what I am talking about? In that case you probably haven't yet subscribed to the SuppVersity Facebook Channel yet. Certainly a mistake, but as you've learned today, it's never too late and once you've read the respective post, you can still mae up for this lapse ;-)

References:

• Abe T, Loenneke JP, Fahs CA, Rossow LM, Thiebaud RS, Bemben MG. Exercise intensity and muscle hypertrophy in blood flow-restricted limbs and non-restricted muscles: a brief review. Clin Physiol Funct Imaging. 2012 Jul;32(4):247-52.
• Fujita S, Abe T, Drummond MJ, Cadenas JG, Dreyer HC, Sato Y, Volpi E, Rasmussen BB. Blood flow restriction during low-intensity resistance exercise increases S6K1 phosphorylation and muscle protein synthesis. J Appl Physiol. 2007 Sep;103(3):903-10. Epub 2007 Jun 14.
• Godfrey R, Theologou T, Dellegrottaglie S, Binukrishnan S, Wright J, Whyte G, Ellison G. The effect of high-intensity aerobic interval training on postinfarction left ventricular remodelling. BMJ Case Rep. 2013 Feb 13;2013.
• Hackett DA, Chow CM. The Valsalva maneuver: Its effect on IAP and safety issues during resistance exercise. J Strength Cond Res. 2012 Dec 4.
• Inagaki Y, Madarame H, Neya M, Ishii N. Increase in serum growth hormone induced by electrical stimulation of muscle combined with blood flow restriction. Eur J Appl Physiol. 2011 Nov;111(11):2715-21.
• Kibiša R, Grūnovas A, Poderys J, Grūnovienė D. Restoration of the work capacity of the skeletal muscle with electrical myostimulation. J Strength Cond Res. 2013 Feb;27(2):449-57. 
• Mero AA, Hulmi JJ, Salmijärvi H, Katajavuori M, Haverinen M, Holviala J, Ridanpää T, Häkkinen K, Kovanen V, Ahtiainen JP, Selänne H. Resistance training induced increase in muscle fiber size in young and older men. Eur J Appl Physiol. 2013 Mar;113(3):641-50.
• Pope ZK, Willardson JM, Schoenfeld BJ. A Brief Review: Exercise And Blood Flow Restriction. J Strength Cond Res. 2013 Jan 28.
• Reeves GV, Kraemer RR, Hollander DB, Clavier J, Thomas C, Francois M, Castracane VD. Comparison of hormone responses following light resistance exercise with partial vascular occlusion and moderately difficult resistance exercise without occlusion. J Appl Physiol. 2006 Dec;101(6):1616-22.

Chicken Legs No More! Building Big Wheels By Walking on the Treadmill: Blood Flow-Restriction Does the Trick!

Image 1:  One thing is certain, the squat, the
"King of all Exercises" will never become obsolete.
(image by verkinetic @Wikipedia)

You have chicken legs, but are too lazy to squat? Well, I guess in this case you will be interested in the results of a recent study by Sakamaki et al. (Sakamaki. 2011) who found that blood flow-restriction is all it takes to induce legs and trunk muscle hypertrophy by just walking the treadmill.

For their study, which was published in the latest issue of the Journal of Sports Science and Medicine the Mikako Sakamaki from the University of Tokyo and his colleagues from the University of Oklahama had 17 "healthy young" men [21.2 (±1.9) years, 1.74 (±0.07) m, and 65.8 (±9.6) kg] participate in 3 weeks of supervised walk training. Following a warm-up, the subjects performedwalking (50 m/minute for five 2-minute bouts, with a 1-minute rest between bouts) on a motor-driven treadmill. The walking speed and duration remained constant throughout the training period.

Figure 1: Relative changes in muscle volume over a 3 weeks training period in blood flow-restricted and control group; note: Only the changes in thigh and lower leg musculature were statistically significant 
(data adapted from Sakamaki. 2011)

Now, 9 randomly selected subjects wore a elastic cuffs that were inflated with a pressure of 160 -230 mmHg during the training sessions (BFR-group). Before and after the 3 week training period muscle cross-sectional areas (CSA) were assessed by magnetic resonance imaging (MRI) and revealed that

[...] MRI-measured upper (3.8%, P < 0.05) and lower leg (3.2%, P < 0.05) muscle volume increased significantly [in the BFR group only!] 

Size and volume of the "gluteus maximus (-0.6%) and iliopsoas (1.8%), [as well] as the muscle CSA of the lumber L4-L5 (-1.0) did not change", however. A result that could be expected, considering the position of the cuffs which restricted blood flow to the lower extremities, while muscles from the gluteus upwards were still well perfused.

Bottom line: For trunk size wheels you probably won't get around doing squats or heavy leg presses to build appropriate strength; but imagine what may happen if you do these in a high volume "Kaatsu style", i.e. with cuffs to restrict blood flow... Jay Cutler, beware!

Arginine + Yohimbine Effective for the Treatment of Erectile Disfunction

Although, this is a topic men do not tend to speak about, statistics say that it bothers more people than one would think: Erectile disfunction. Certainly, Viagra & Co are the most popular tweaks for "getting it up" again, a new study from Iran (Akhondzadeh. 2010), however, suggests that a combination of arginine + yohimbine may prove effective, as well. In a 4-week, double blind study of parallel groups of patients with mild to moderate ED, the scientists report a significant difference in ED within the group supplemented with a one capsule of SX (a commercial preparation consisting of l-arginine + yohimbine):

The difference between the two groups was significant at week 4 (endpoint) (P=0.03). Four adverse events were observed over the study. The difference between the SX and placebo was not significant in the frequency of adverse events.

Unfortunately, the funding of the study suggests that there may have been a certain bias towards "proving" the advertisement-claims of the producers and financial supporter of the study, Nature Gift.

Figure 1: Comparison of baseline and endpoint of the two groups (week 4) based
on erection domain of IIEF Sscore.NS: non significant and *=P<0.05.

Although you better take the results illustrated in figure 1 with some skepticism, both arginine and yohimbine have long been known to improve blood flow to the testis and help with certain types of erectile dysfunction, so trying respective products, may eventually produce results - at least, for some...

2g Arginine /Day Induce Vasolidation and Increase VO2Max in Male Soccer Players

Regular readers of the SuppVersity will know that - despite the recent bashing of arginine by the some supplement producers - I like this universal amino acid AND studies supporting the notion of athletes being able to benefit from arginine supplementation keep coming. The most recent one was done by Kamil et al. (Kamil. 2010) and investigated the effect of 2g pure l-arginine on vasolidation and VO2Max in soccer players. Their findings were as follows:

Oral supplementation of L-arginine significantly (p<0.01) decreased blood pressure indices and increased VO₂max (p<0.01), blood flow (p<0.05), femoral artery diameter (p<0.05) and urea levels (p<0.05). There was no change in blood lipid levels (p<0.05). No significant changes were noted in the placebo and control groups.

The increase in VO2Max, as shown in Table 1 was relatively low, though. Yet, it's statistical significance stands out of question.

	L-Arginine	Placebo	Control
Pre	56.43 ± 3.7	57.85 ± 6.8	56.52 ± 3.3
Post	57.15 ± 3.3 **	57.48 ± 6.9	56.55 ± 3.1

Table 1: Mean (±SD) pre- and post-study values of VO₂max (ml/kg/min) in male soccer players

If this is no reason not to dump your good old "1st generation"-preworkout products (e.g. NO Xplode, White Flood, Super Pump 250, VPX Shotgun), the main working ingredient of which is - guess what: arginine.On a side note: After trying about every of the new "super-mega NO-booster" from PreSurge-Unleashed to Anadraulic State GT, I have just returned to MHPs Dark Rage, which, to my mind, is still among the most comprehensive and effective pre-workout products on the market - you already knew it: an arginine-based product, as well.

Blood Flow Restriction Boosts Strength and Muscle Gains on Low Intensity Bench Press Exercise

Would you wear elastic plastic cuffs on your arms while doing 4 sets of 75 reps at 30% of your 1-RM max [what you can bench for a single rep] on the bench press? No? Well, you better revise your initial skepticism in view of the results of a recent investigation (Yasuda. 2010) on the effect of blood flow restriction on upper body muscle growth and strength gains.

Effect of training on strength and muscle size for blood flow restricted (BFR) and normal bench press (CON) exercise. (data adapted from Yasuda. 2010)

Low intensity training triggered muscle growth and increased strength only in blood flow restricted trainees. This is of particular interest for bodybuilders and fitness-athletes, because it suggests that by "pumping", i.e. by deliberately increasing blood supply to your arms on high rep sets at the end of an intense training session, one may well achieve similar effects and thus further stimulate muscle growth by combining the best of the two worlds (HIT vs. PUMP).