Sunday, February 17, 2013

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.

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 ;-)

  • 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.