Build Size & Strength With Isometric Co-Contractions: 4% Increase in Arm Circumference and ~20% More Strength With Less Than 10 Minutes of "Flexing" Per Week

Big guns without weights? True - the question yet remains: "How big?"

I am psyched and the reason is the advanced access publication of the results of the latest study from the Department of Sports and Life Science at the National Institute of Fitness and Sports in Kanoya, Japan (Maeo. 2013b).

Why? Well, it claims to solve two of the most urgent issues that keep our sedentary fellow men (and women ;-) from working out: The lack of equipment and the lack of time, exactly those two factors the average American and European slacker pleads as an excuse for not making the necessary, since potentially life-saving physical investments into "metabolic currency" (this is a term my good friend Carl Lanore uses to refer functional muscle mass).

"Big guns without weights? You're kiddin', bro!"

Actually the idea of using simultaneous voluntary contractions of antagonistic muscle pairs (aka co-contraction) to improve muscle strength in the absence of external apparatuses is not new. The voluntary co-con traction of elbow flexors and extensors you can see in the photo in the red "This is how it's done" box, for example, may look ludacris (imagine doing that at the gym), its efficacy is however backed by previous research and its working principle is as simple as ingenious: Biceps and triceps, i.e. elbow flexor and extensor, produce resistive forces that act against each other (Tyler. 1986), so that one muscle actually "trains" the other.

You can learn more about training biceps & triceps at the SuppVersity

Training the Individual Parts of the Triceps

Find the Best Triceps Exercises (EMG Data)

Explore the Best Biceps Exercises (EMG Data)

Train Bis + Tris on a Single Day & Grow!

Add 0.5 Inch To Your Arms in 5 Minutes

Disproportionate Triceps Growth? Is It Real?

In their initial investigation into the effects of muscular co-contraction, the results of which have been published in the International Journal of Sports Medicine in July 2013 (Maeo. 2013b), the researchers have been able to confirm that the muscular activity that occurs during the voluntary co-contractions is a sufficient training stimulus for improving the strength capability of both muscles (Maeo et al. 2013a).

"In fact, previous studies that adopted co-contraction training for elbow flexors and extensors (Driss et al. 2013; MacKenzie et al. 2010; Maeo et al. 2013) found significant increases in the strength capability, as well as agonist electromyographic (EMG) activity during isometric maximal voluntary contraction (MVV) (MacKenzie et al. 2010; Maeo et al. 2013), of the two muscle groups. the previous findings cited above support the idea that co-contraction can be an effective training modality, which does not require any external apparatus, for increasing muscle strength." (Maeo. 2013b)

So, while we are pretty certain that "standing there and contracting your bis and tris" can increase muscle strength (learn how to build strength), there is a scarcity of evidence that would allow us to make reliable statements about the effects of voluntary muscular cocontractions on muscle size (learn how to build muscle). It is thus only logical that the intention of Sumiaki Maeo's, Yasuhide Yoshitake's, Yohei Takai's, Tetsuo Fukunaga's and Hiroaki Kanehisa's follow up study was "to clarify neuromuscular adaptations following 12-week maximal voluntary co-contraction training" (Maeo. 2013b). In that, the researchers hypothesized that

• 

  If you feel like a shadow of yourself, betaine may help | learn more

  the training modality with maximal voluntary co-contraction would increase both size and strength capability of the exercised muscles, and
• training unsing co-contractions does not change involuntary coactivation level during MVC of the agonist alone

In other words: The researchers wanted to make sure that (a) this form of training builds strength and muscle and (b) that it does not have lasting potentially performance decreasing effects on the co-activation of the triceps / biceps, when you actually want to use only one of them (imagine you want to curl the weight up and your triceps works against you).

The study protocol

To satisfy their research interest, the researchers from the Department of Sports and Life Science at the Japanese National Institute of Fitness and Sports in Kanoya recruited 16 healthy young men.

Don't neglect the proven benefits of periodization: "Six Weeks On + Three Weeks Off" Macrocycle Yields Identical Gains Strength and Size Gains as Continuous Training | more

The guys, who were in their early twenties, lean, healthy and habitually active, but not involved in regular exercise programs with a duration and frequency of more than two 30 minute exercise sessions per week, were then randomly assigned to two groups: A training group (T) with 9 participants and an inactive control group (C) with 7 participants. It goes without saying that all participants had to abstain from additional physical activity over the course of the whole study period during.

In those 12 weeks the subjects in the the subjects in T group participated in a 12-week training program with maximal voluntary co-contraction of the elbow flexors and extensors of the right arm 3 times per week.

Usually this would be the paragraph of this SuppVersity article, where I would give you a concise summary of the exercise protocol. In view of the fact that I doubt that many of you are actually familiar with muscular co-contractions, I decided to use a somewhat abridged quote of  the scientists' lengthy, but comprehensive explanation of the procedure (see red box).

This is how it's done: In a standing position with the feet shoulder width apart, upper arm vertical to the ground, the elbow joint at 90° (full extension = 180°), forearm in a neutral (middle of supinated and pronated) position you will perform a 4-s muscle isometric co-contraction followed by 4-s muscle relaxation (total volume: 10 times per set, 5 sets per session; rest: 2 min between sets). Make sure to perform each voluntary co-contraction as rapidly as possible and sustain maximal effort for full 4s!

Basically what the subjects were doing could be summarize as 10x4s maximal isometric muscle contractions with 4s break between each contraction for one set and 5 of these sets with an interim of 2 minutes between each of them three times per week.

Now for those surprisingly impressive results

If you do the math and add up the actual time under tension for this 12-week experimental intervention, you will get 10 × 4s isometric contractions × 5 sets × 3 / week × 12 weeks = 7200s or 2h. That's not really much considering the fact that it lead to strength and size increases of +15% / +27% and 4% / 4% in the elbow flexors (biceps) and extensors (triceps) of the previously more or less untrained, but no necessarily sedentary subjects.

Figure 1: Pre vs. post measures of muscle thickness, MVC torque and coactivation level (Maeo. 2013b)

As you can read in the small box in Figure 1 the increases in size and strength did not occur rapidly after two or three weeks and were then followed by a plateau.In fact, the researchers recorded statistically significant strength and measurable, but statistically not yet significant size gains after 4 weeks.

Probably effective for increases in dynamic performance, as well

Now, brute strength and a huge muscle mass are by no means what all athletes are striving for. For many athletes improving their dynamic performance and strength, which would have required the measurement of changes in isokinetic torques for elbow flexors and extensors in both eccentric and concentric conditions, is at least as important. It is thus more than noteworthy that data from Maoe et al.'s previous 4-week study (Maeo. 2013a),

"[...]in which untrained individuals conducted 4-week co-contraction training, showed that the co-contraction training significantly increased isokinetic torques for elbow flexors and extensors in both eccentric and concentric conditions." (Maeo. 2013b)

As the researchers rightly point out, we do thus have reason to believe that "contraction training is also effective for improving dynamic performance, at least for untrained individuals" (Maeo. 2013b). With respect to trained athletes, the reaserchers do yet argue that they'd require higher exercise intensities to achieve additional improvement in muscle strength than non-athletes (Alway. 1992; Cormie. 2011). This, as well as the emphasis sports specific training puts on ballistic, plyometric, and weightlifting exercises involving sports-specific and/or multi-joint movements (Cormie. 2011), make it difficult to believe that similar training results could be achieved by performing maximal voluntary co-contraction.

Suggested read: "Advanced Trainees Benefit from Increased Training Volume!" | more

Great! But nothing a trained individual can benefit from? It's obvious that someone with a 50cm biceps is not going to add another 2cm in 12 weeks in the course of which he lies around on the sofy and performs 5 sets of voluntary maximal co-contructions thrice a week.

This does yet not mean that this relatively unknown training stimulus cannot make a valuable addition to his training regimen... and let's be honest, haven't we all had a pro-bodybuilder give us a bro-scientific lecture on how flexing, in and out of itself nothing, but a voluntary maximal contraction (albeit not necessarily with antagonistic co-contractions for every muscle part) is a vital part of any hypertrophy oriented strength training routine?

References:

• Alway, S. E., Grumbt, W. H., Stray-Gundersen, J. & Gonyea, W. J. (1992). Effects of resistance training on elbow flexors of highly competitive bodybuilders. Journal of Applied Physiology, 72(4), 1512-1521.
• Cormie, P., McGuigan, M. R., & Newton, R. U. (2011). Developing maximal neuromuscular power. Sports medicine, 41(1), 17-38.
• Maeo, S., Yoshitake, Y., Takai, Y., Fukunaga, T., & Kanehisa, H. (2013). Neuromuscular adaptations following 12-week maximal voluntary co-contraction training. European Journal of Applied Physiology, 1-11.
• Maeo, S., Yoshitake, Y., Takai, Y., Fukunaga, T., & Kanehisa, H. (2013). Effect of short-term maximal voluntary co-contraction training on neuromuscular function. International journal of sports medicine, (EFirst). 
• Tyler, A. E., & Hutton, R. S. (1986). Was Sherrington right about co-contractions?. Brain research, 370(1), 171-175.

Detraining and Training Periodization: 6 Months On "Six Weeks On + Three Weeks Off" Macrocycle Yields Identical Gains Strength and Size Gains as Continuous Training

"Is everyone at home taking some time off to recover + prime future muscle growth?"

Human beings are creatures of habit. This is particularly true, when it comes to those things and procedures we either like or enjoy or have found to be highly conducive to our goals, in the past. Just like some people simply won't drop their beloved Twinkies and Ding Dongs, although they know that these sugar bombs are bad for them, and others tend to stick to whatever dietary regimen has allowed them to lose 20lbs of body weight in the past, despite the fact that this "trick" has long ceased working for them, many "recreationally active" individuals (aka gymrats) are totally reluctant to any form of carefully planned deviation of their training regimen.

Six weeks on, three weeks off - for better or for worse!?

If anything, switching gears from a more hypertrophy to a more strength training oriented program, or vice versa, is probably the one modification most trainees could come to terms with. The notion to take one, let alone three weeks off after the completion of a 6 weeks mesocycle, on the other hand, scares the hack out of 99% of the ambitious strength trainees. Unjustly, as a study that's been published less than one week ago in the online edition of the European Journal of Physiology goes to show you (Ogasawara. 2012).

Systematically periodized trainig routines (yet often with only one detraining phase per season) are among the various reasons professional athletes are at a lower risk of developing the athletes' triad than overambitious gymrats.

As surprising as it may sound to the "I will lose my precious muscle" faction, the results of the study Riki Ogasawara and his colleagues from the University of Tokio conducted do actually just confirm what we knew all along:

"[A]fter short-term (>1 month) cessation of training (detraining), muscle adaptation responses may return to their initial levels, and the effects of retraining after short-term cessation on muscle growth are comparable with those observed during the early phase of training." (Ogasawara. 2012)

If we further acknowledge that the loss of protein from the muscle during the detraining phase is much slower than the rapid gain, during the early weeks of (re-)training, it should be obvious that any retraining phase will lead to overall increments in skeletal muscle cross sectional area that will easily overcompensate the small amount of size your muscles will have lost during the comparatively short phase without physical exercise.

Based on the actual results of previous research by Narici et al, Bemben et al. Hakkinen et al. and Hulmi et al., Ogosaware et al. propose the following example to illustrate this effect:

*Why is it problematic that the study participants were untrained? With the initial growth response to weight training being much more pronounced in previously untrained individuals, it is very likely that the same is going to be the case for the similarly pronounced response to "retraining" after a three-week detraining phase. This does not generally speak against the usefulness and maybe even the need for well-planned periodization in advanced trainees, but it renders the concept of a complete three weeks lay-off (=classic detraining) at least questionable. Read my comments towards the end of this post for possibly better-suited alternatives.

"[...] assuming that the decrease in thigh muscle CSA during 3 weeks of detraining is 2.1 % (estimated at 0.10 % per day and 21 days), and the increase in muscle CSA during 6 weeks of retraining is 5.9 % (estimated at 0.14 % per day and 42 days), the increase in muscle CSA during a 3-week detraining/6-week retraining period (estimated at 0.06 % per day during 9 weeks) would be 3.8 %. The estimated value of 0.06 % per day is similar to values obtained in previous studies, where the average increase in thigh muscle CSA was reportedly around 0.05 % per day." (Ogasawara. 2012)

Well, I see this alone can't convince you, right? What about the detailed results of Ogasawara very own study, then? Allegedly, it was done in untrained individuals*, 14 young men (age 25 ± 3 years, standing height 1.72 ± 0.06 m, body mass 65 ± 10 kg), but the results the training regimen the researchers characterize as follows,

"Both groups performed high-intensity, free-weight bench press exercise training 3 days per week. [...] Training intensity was set at 75 % of one repetition (rep) maximum (1-RM), and training volume was set at 3 sets of 10 reps (with 2–3 min rest between sets). To ensure an adequate training load, all training sessions were overseen by a supervisor. Training load was renewed every 3 weeks, and, if subjects could perform 12 reps or more at the 3rd set during training sessions, the training load was increased by about 5 % for the next training session." (Ogasawara. 2012)

speak for themselves and were virtually identical in both groups - regardless of whether the subjects trained for 24-weeks continuously (CTR), or performed their regimen in the form of two cycles of 3-week detraining/6-week retraining periods after an initial 6-week mesocycle.

Figure 1: Relative changes 1-RM and maximal voluntary contraction (MVC) + time-course of these changes (left); time-course of relative changes in cross sectional area in triceps bracchii (top, right) and pectoralis major (bottom, right; based on Ogasawara. 2012)

Aside from the already mentioned training status of the study participants there are yet two other things I am missing in this study:

Figure 2: Just in case you've forgotten about that - different muscles react in different ways to modulations in training volume. So why would they react identically to off-times? Moreover if legs benefit most from a higher training volume, wouldn't it be likely that they suffer most from longer periods of detraining?

1. Detailed data on the pre / post body composition. The identical increase in body weight (+2%) is not of interest to me (and probably to only very few of you) and the simple assumption that identical body weight gain + identical CSA gains of triceps brachii (TB) and pectoralis major (PM) would translate into identical changes in total body fatness / muscularity is about is unwarranted (see link in figure 2).
2. A realistic full-body workout routine: The low volume chest only workout regimen is not just unrepresentative of a real workout protocol, it does also raise the question if other body parts as the legs, for example, would not respond very differently to a three week lay-off phase (see figure 2 + respective reference to a previous post on training volume).

As far as the pectoralis and triceps specific gains in muscle size and strengths in strength training newbies are concerned, the results of the study at hand do however add  o the initially mentioned practicability of a simplistic, but effective "6 weeks on, 3 weeks off" approach to periodization, which - and this is a novel finding compared to Ogasawara's study from last year (Ogasawara. 2011) - does still work even in the third mesocycle (take another look at figure 1 the "catch up growth" does not diminish!).

Conclusion + "What about advanced athletes?"

Despite the fact that the last mentioned sustainability of this approach over a pretty long time period (24 weeks, i.e. 3x complete macrocycles) would indicate that a similar approach will work for trained (maybe even elite) athletes as well, I am pretty convinced that a period of three weeks of complete idleness is not the optimal periodization strategy for advanced trainees, because:

Possible alternatives for advanced athletes: Rather than taking a complete 3-week time out from all athletic endeavors, you can to stick to ...

• a maximal complete off-time of 1-week (as in not doing anything), 
• a 2-3 weeks of active off time (as in going on vacation w/ regular non-exhaustive physical activity), or
• the incorporation of a tapering regimen as described in Part VI of the Step By Step Guide to Your Own Workout

Alternatively you can combine / mix one or two of these (you won't go on vacation every 6 weeks, will you?)

• The discrepancy between the accrual of skeletal muscle protein and the loss of the latter in response to total laziness gets lower, if not totally reversed, the bigger you get. Consequently the added bonus of "faster gains" upon recommencing the training will diminish, or even disappear completely.
• Many more or less "professional" trainees follow dietary regimen that are not sustainable, when they are not training. During a complete time-off of three weeks without any alternative "outlet", the chances to gain fat are thus much higher for them, than for the average beginner, who - if anything - guzzles a protein shake after each of his three weekly training sessions.
• Competitive amateur athletes who are training 5x a week or more actually run the risk of both, physical and psychological withdrawl symptoms, when they simply stop training altogether (another argument in favor taper, if you asked me; see infobox on the right).

Regardless of which of the alternatives in the blue infobox next to the three arguments that make a complete 3-week lay off at least questionable for advanced / professional trainees you pick, if you decide against the "No, that's bullocks, I train day-in-day-out till I drop" approach, there is one thing you should keep in mind:

If you are not the one in a million expection from the rule,
you cannot simply "play this by ear"!

Periodization requires planning and planning is done in advance and not in a "well, I feel like I could go for another week" or "damn, I am tired today, let's take three weeks off and see how it goes then" fashion. Alright?

References:

• Bemben DA, Fetters NL, Bemben MG, Nabavi N, Koh ET. Musculoskeletal responses to high- and low-intensity resistance training in early postmenopausal women. Med Sci Sports Exerc. 2000: 32:1949–1957
• Hakkinen K, Newton RU, Gordon SE, McCormick M, Volek JS, Nindl BC, Gotshalk LA, Campbell WW, Evans WJ, Hakkinen A, Humphries BJ, Kraemer WJ. Changes in muscle morphology, electromyographic activity, and force production characteristics during progressive strength training in young and older men. J Gerontol A Biol Sci Med Sci. 1998; 53:B415–B423
• Hakkinen K, Alen M, Kallinen M, Newton RU, Kraemer WJ. Neuromuscular adaptation during prolonged strength training, detraining and re-strength-training in middle-aged and elderly
  people. Eur J Appl Physiol. 2000; 83:51–62.
• Hakkinen K, Alen M, Kraemer WJ, Gorostiaga E, Izquierdo M, Rusko H, Mikkola J, Hakkinen A, Valkeinen H, Kaarakainen E, Romu S, Erola V, Ahtiainen J, Paavolainen L. Neuromuscular adaptations during concurrent strength and endurance training versus strength training. Eur J Appl Physiol. 2003; 89:42–52
• Hulmi JJ, Kovanen V, Selanne H, Kraemer WJ, Hakkinen K, Mero AA. Acute and long-term effects of resistance exercise with or without protein ingestion on muscle hypertrophy and gene expression. Amino Acids. 2009; 37:297–308.
• Narici MV, Hoppeler H, Kayser B, Landoni L, Claassen H, Gavardi C, Conti M, Cerretelli P. Human quadriceps crosssectional area, torque and neural activation during 6 months strength training. Acta Physiol Scand. 1996; 157:175–186
• Ogasawara R, Yasuda T, Sakamaki M, Ozaki H, Abe T. Effects of periodic and continued resistance training on muscle CSA and strength in previously untrained men. Clin Physiol Funct Imaging. 2011 Sep;31(5):399-404.
• Ogasawara R, Yasuda T, Ishii N, Abe T. Comparison of muscle hypertrophy following 6-month of continuous and periodic strength training. Eur J Appl Physiol. Oct 06, 2012. 

Muscle Building Takes Time. Less in Newbies, Though: 9.6% More Muscle in 8 Weeks

"Patience is a virtue!" Many bodybuilders and fitness enthusiasts have to learn this the hard way - even on drugs, muscles won't grow (hypertrophy) within days and visible gains in lean muscle mass will take years or month. Although the results of a recent study (DeFreitas. 2011) done by scientists from the University of Oklahoma won't help to overcome the delay between training induced muscle stimulus and physiological hypertrophy response, the observations of DeFraitas et al. are nevertheless interesting.

By the means of weekly testing the scientists wanted to determine the "precise time course of skeletal muscle hypertrophy" in response to 8 weeks on a specifically designed high intensity resistance training program in 25 healthy, sedentary men. The measured outcomes were whole muscle cross-sectional area (CSA) of the dominant thigh (via computer tomography) and isometric maximum voluntary contractions (MVC). 

After only two training sessions (W1) [=week 1], the mean thigh muscle CSA increased by 5.0 cm² (3.46%; p < 0.05) from the pre-testing (P1) and continued to increase with each testing session. It is possible that muscular edema may have inXuenced the early CSA results. To adjust for this possibility, with edema assumedly at its highest at W1, the next significant increase from W1 was at W3. W4 was the Wrst signiWcant increase of MVC over P1. Therefore, signifcant skeletal muscle hypertrophy likely occurred around weeks 3–4.

While edema, unquestionably, are one possible reason for the sudden increase in "muscle mass" being a 'sedentary newbie' to strength training may well be another factor contributing to the immediacy of the muscle gains (do not expect to see similar results as an experienced athlete!). The scientists reliance on sedentary subjects compromises the significance of the whole study (in view of what athletes and gymrats may expect), thus the measured overall gains, impressive +13.9 cm² (9.60%) CSA, appear hardly transferable to a "reasonably" trained group of subjects, as well.

Figure 1: Development of muscle size (measured as CSA of thigh muscle) and force (measured as MCV) in 25 formerly sedentary subjects on an 8 week high intensity strength training program (DeFreitas. 2011)

Comment: Its really a pitty that out of monetary and organizational reasons all these studies are done on newbies, whom you could send work on a construction site for 8 weeks and see immense gains in strength and muscles, when they do not get hit by a block of concrete. So, do not feel discouraged if - in the course of the whole last year, you did not gain +13.9 cm² in your tigh muscle. You are probably just to athletic already ;-)

Science Round-Up Seconds: Stevia, Cancer & Fertility. What is the Verdict? Exercise, Hunger & GLP-1. Can a Workout Fill You Up? Postactivation Potentiation & Personal Bests. 8% More Maximal Power After 5s Max. Voluntary Contraction?

Other news: Classic cardio ramps up GLP-1 and "posing" increases your maxes by up to 8%.

If you have already downloaded and listened to yesterday's installment of the SuppVersity Science Round-Up, you will probably be aware that the first thing I am going to do in today's Seconds is to (re-)address the stevia issue (read up on previous stories about Stevia here at the SuppVersity).

If I recall that correctly, I did in fact forget to mention something that's actually important if you want to get the whole picture - the gut microbiome! But before we tackle this one, let's not forget that there are a couple of other news stories which did not make it into the 60min show, news on the effects of LISS on GLP-1 and the potentiation of the post-activation potentiation effect. Sounds interesting, then let''s go for it!

Is stevia toxic, does it cause cancer and infertility? 

Let me start with the bottom line first. The currently available scientific evidence clearly suggest that stevia is safe to consume. Or, as "real" scientists (not that I would not consider myself a scientist, but without a single published paper in this domain of science, I am certainly not an authority ;-) write in their papers:

What was that about the microbiome? I forgot to mention that the "bad" aglycol aka "steviol" is also produced from the benign and usually not even absorbed pure steviosides and is thus not something you'll find only in "natural" stevia products. That being said, Wingard et al. observed in 1980 already that steviol is readily excreted via the billary pathway in the feces (Wingard. 1980; confirmed by Nakayama. 1986). You may thus be exposed to small amounts of steviol no matter what, but that's nothing your body cannot dispose of.

"The recent suggestions that steviol glycosides present a muta-genic – and therefore carcinogenic – risk to consumers are not sup-ported by actual test results. The paper making this claim by Matsui et al. (1996a) was published prior to most of the papers assessing the genotoxic risk of steviol glycosides as well as several expert panel reports and a review by Brusick in 2008. The database of genotoxicity studies for steviol glycosides and steviol as it currently stands, combined with a lack of evidence for neoplasm development in rat bioassays (Aze et al., 1991; Xili et al., 1992; Toyoda et al., 1997; reviewed by Carakostas et al., 2008, 2012; EFSA, 2010), is adequate to establish the safety of these food ingredients with respect to their genetic/carcinogenic potential." (Urban. 2013)

And with respect to the infertility claim, Geuns et al. write in their very detailed review from 2003:

"The results of a decrease of live birth rate in rats (Planas and Kuæ, 1968) by Stevia decoctions were refuted by Shiotsu (1996) who did more reliable experiments with many more animals using methods as similar as possible to the methods used by Planas and Kuc. No effect on general condition, body weight, water consumption, live birth rate or litter size was found. No effects of stevioside were found on fertility or reproduction in mice (Akashi and Yokoyama, 1975), rats ( Mori et al., 1981, Xili et al., 1992 and Sinchomi and Marcorities, 1989) or hamsters (Yodyingyuad and Bunyawong, 1991).

No significant effect was found on spermatogenesis, nor on the interstitial cell proliferation and tumor formation in the testes of F344 rats fed a ration containing up to 1% stevioside (95.2% purity) for 22 months (Yamada et al., 1985).

If you are either a newcomer to the SuppVersity or simply cannot remember the summary of selected stevia research from September last year, I suggest you go back in the archives and read up on "More Than Super Sweet: More Scientific Evidence, More Potential Implications for Weight Loss &amp; -Maintenance, Anti-Diabetic &amp; -Autoimmune and Even Pro-Anabolic Effects" (learn more) Some of the benefits are btw. mediated by the same stuff that's toxic in in-vitro studies...hormesis, you know ;-)

Whereas Melis (1999) suggested a possible decrease of the fertility of male rats by a very high dose of Stevia extract, Oliveira-Filho et al. (1989) who administered extracts with similar stevioside content stated that there is certainly not an effect on male fertility. It is not sure that the observed effects were due to the stevioside present in the extract. It should also be mentioned that the used extract concentrations were extremely high, at the start of the experiments even 5.34% of the body weight (or around 5.3 g stevioside/kg bw). For an adult person of 65 kg this means 3.47 kg of dry Stevia leaves or about 34.7 kg fresh leaves/day, i.e. more than 50% of the body weight! The significance of such experiments where only one extremely high concentration was tested, should be questioned. Melis' results are also in contradiction with the above and below cited studies that could not reveal any effect on fertility of male or female animals." (Geuns. 2003; my emphases)

Much ado about nothing? Well, in the end it may seem so and the preponderance about freakin' out over every potential and 0.5% marginal possibility that something you do or eat could be wrong or toxic certainly ain't healthy. On the other hand, it's always good to exhibit a certain degree  of suspiciousness - just do me favor: Do that towards both the good and the bad news!

Scheduled news that did not make it into the live show

The fat burning benefits of hydroxypropyl-distarch phosphate from waxy maize starch  (WMHDP) are - at least in part - also mediated by increases in GLP-1 production (read more)

Short and long-term effects of exercise on appetite and metabolism regulating hormones -- (Ueda. 2013) As a SuppVersity reader and SHR listener, you are no stranger to the acronym GLP-1 and the effects the "satiety hormone" it stands for has on your desire to eat and, more importantly, your metabolisms willingness to use not store the energy from the food you consume (learn more).

In a soon to be published paper, Shin-ya Ueda and colleagues report that chronic exercise, in this case 3x/week 60min of light intensit (65% of VO2max) cardio on a treadmill and/or cycle ergometer results in a statistically highly significant increase in GLP-1 in response to exercise.

Usually I don't like to repeat myself, but I would probably have missed the main important message here, if I were just skimming the above: The 20 healthy middle-aged women who participated in the 12-week experiment did not simply have higher GLP-1 levels after a meal. No, the post-exercise levels of GLP-1 and the other satiety hormone PYY increased hours before the ladies even got their next meal.

Figure 1: GLP-1 (pmol/ml; left) and PYY (pmol/ml; right) response to exercise before and after (0, 30, 60 min) a 80min (60 min effective training + 20min warm-up, cool-down etc.) supervised workout before (untrained) the 12-week exercise intervention and after (trained) the 12-week exercise intervention (Ueda. 2013)

In conjunction with the significant correlation of GLP-1 with the reduction in body weight the study participants achieved over the course of the course of the 12x3 = 36 supervised exercise session, this was reason enough for the scientists to hypothesize that...

"[...] that the ability of exercise training to create a negative energy balance relies not only directly on its impact on energy expenditure, but also indirectly on its potential to modulate energy intake." (Ueda. 2013)

So, does exercise "just make you hungry". No, it turns you into a satisfied fat burning machine - and that even if it's just 3x60min of LISS per week.

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Training increases the efficacy of 5-6s maximal contractions to before a maximal voluntary effort (Miyamoto. 2013) I guess you will be aware that Superman usually does a 5-6s maximal voluntary contraction (MVC) while checking out if everybody is watching before he eventually does the deed and lifts the car that has just overrun the beautiful blond bombshell with a "single-armed deadlift", right? Good, because if you know that, I don't have to explain why the scientists from the Waseda University in Japan 21 healthy male subjects perform a 5s MVC before they did their maximal voluntary concentric knee extensions 1, 3 and 5 minutes, thereafter.

Figure 2: Voluntary concentric torque on knee extensions after previous peak contractions before (left) and after (right) in the trained and untrained study participants.

What I probably still have to tell you though is that the "after" values you see in figure 2 were taken after 12-weeks of doing 5x 8 reps with 80% of the one-repetition max in a standard knee extension machine. Ok, I have to admit that the actual training effect is not really impressive, but since most of you have it already built in (after all, you probably train for more than 12-weeks already, right?) doing a single 5s maximal voluntary contraction before a max-effort trial is an easy and time-efficient (1 min!) way to increase your performance by superman-like 8%! What this funky technique is called like? Postactivation Potentiation - nice alliteration, isn't it?

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That is it, for the day - at least for the Seconds. If you don't know what to do before the weekend begins, browse over to the SuppVersity Facebook Wall and check out news on

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  If you have not done so, already, click here and teach yourself "How to Make the Correct Fish choices"? There is luckily way more swimming around in our oceans than farmed salmon with it's more than 4x elevated n6:n3 ratio (compared to wild salmon, learn more)

  Salmon in the vicious cycle of soy supplementation - Scientists try to come up with a certain bacteria that could protect farmed salmon from the junk, ah... soy it's fed (read more)

• Alpha lipoic acid (ALA) helps otherwise healthy schizophrenics on heavy anti-histamine regimen to lose weight - 2x 1gram of regular ALA does the trick (read more) 

• People who were breastfed as kids have healthier eating habits in their adulthood - Interestingly, this effect did not depend on social class at birth or later in life and occurred irrespective of smoking status, alcohol intake or reported physical activity.

Once you've done that, you first make sure that you did not miss part three of my interview with Sean Casey and then get off the screen and into the night, family or whatever real life, I'd hope you did not give up on after you bought your latest iPhone ;-)


References:

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• Aze Y, Toyoda K, Imaida K, Hayashi S, Imazawa T, Hayashi Y, Takahashi M. [Subchronic oral toxicity study of stevioside in F344 rats]. Eisei Shikenjo Hokoku. 1991;(109):48-54.
• Carakostas MC, Curry LL, Boileau AC, Brusick DJ. Overview: the history, technical function and safety of rebaudioside A, a naturally occurring steviol glycoside, for use in food and beverages. Food Chem Toxicol. 2008 Jul;46 Suppl 7:S1-S10.
• Geuns JM. Stevioside. Phytochemistry. 2003 Nov;64(5):913-21. Review.
• Matsui M, Matsui K, Kawasaki Y, Oda Y, Noguchi T, Kitagawa Y, Sawada M, Hayashi M, Nohmi T, Yoshihira K, Ishidate M Jr, Sofuni T. Evaluation of the genotoxicity of stevioside and steviol using six in vitro and one in vivo mutagenicity assays. Mutagenesis. 1996 Nov;11(6):573-9.
• Melis MS. Effects of chronic administration of Stevia rebaudiana on fertility in rats. J Ethnopharmacol. 1999; 167:157–161 
• Miyamoto N, Wakahara T, Ema R, Kawakami Y. Further Potentiation of Dynamic Muscle Strength after Resistance Training.  Medicine & Science in Sports & Exercise. Publish Ahead of Print
• Mori N, Sakanoue M, Takcuchi M, Shimpo K, Tanabe T. Effect of Stevioside on fertility in rats. J Food Hyg Soc Jpn. 1981; 22:409–414.
• Nakayama K, Kasahara D, Yamamoto F. Absorption, Distribution, Metabolism and Excretion of Stevioside in Rats. Shokuhim Eiseigaku Zasshi. 1986; 27(l):l-8.
• Oliveira-Filho RM, Uehara OA, Minett CASA, Valle LBS. Chronic administration of aqueous extract of Stevia rebaudiana (Bert.) Bertoni in rats: endocrine effects Gen. Pharmac. 1989; 20:187–191. 
• Planas GM, Kuæ J. Contraceptive properties of Stevia rebaudiana Science. 1968;162:1007.
• Shiotso S. Fertility study of Stevia decoction in rats. Tech J Food Chem Chemicals. 1996; 4:108–113.
• Sinchomi D, Marcorities P. Etude de l'activité anti-androgénique d'un extrait de Stevia rebaudiana Bertoni. Plantes médicinales et phytothérapie. 1989; 23:282–287.
• Toyoda K, Matsui H, Shoda T, Uneyama C, Takada K, Takahashi M. Assessment of the carcinogenicity of stevioside in F344 rats. Food Chem Toxicol. 1997 Jun;35(6):597-603.
• Ueda SY, Miyamoto T,  Nakahara H, Shishido T, Usui T, Katsura Y,  Yoshikawa T, Fujimoto S: Effects of exercise training on gut hormone levels after a single bout of exercise in middle-aged Japanese women. SpringerPlus. 20132:83.
• Urban JD, Carakostas MC, Brusick DJ. Steviol glycoside safety: is the genotoxicity database sufficient? Food Chem Toxicol. 2013 Jan;51:386-90.
• Wingard RE Jr, Brown JP, Enderlin FE, Dale JA, Hale RL, Seitz CT. Intestinal degradation and absorption of the glycosidic sweeteners stevioside and rebaudioside A. Experientia. 1980 May 15;36(5):519-20.
• Yamada A, Ohgaki S, Noda T, Shimizu M. Chronic toxicity of dietary Stevia Extracts. J Food Hyg Soc Jpn. 1985; 26:169–183.
• Yodyingyuad V, Bunyawong S. Effect of stevioside on growth and reproduction. Human Reproduction. 1991; 6: 158–165.
• Xili L, Chengjiany B, Eryi X, Reiming S, Yuengming W, Haodong S, Zhiyian H. Chronic oral toxicity and carcinogenicity study of stevioside in rats. Food Chem Toxicol. 1992 Nov;30(11):957-65.

Training, Detraining, Retraining: Build Bigger and Stronger Muscles by Taking 3 Weeks Off!?

Image 1: This dog obviously knows how beneficial it is to take 3 weeks off and detrain. If we go by his physique, he did probably not realize that without (pre-)training and retraining the distinct line between detraining and laziness becomes as blurred - as blurred, by the way, as many it is for training junkies like me ;-)

I plead guilty! Guilty of not taking enough time off - against better judgment. In that, it is not the idea that I would "lose muscle" that urges me to the gym, it is not that I would be afraid to get fat and I could probably even stifle my desire to lift heavy objects, if it was not for the little man in my ear who keeps telling me: "Well, you won't get fat and you won't lose muscle, but think about it: You are fit, young and strong! Why waste your time idling around? Go for it hit the weights and let the veins pop" ... and alas, his words are too convincing to put my gymbag back into the locker and write one of the 237 blogposts I am constantly thinking about and never finding the time to compile. Thanks to Steven Arcera, who, by the way, is somewhat of the productive, digital counterpart of the little man in my ear, as he is constantly pricking new ideas into my brain by posting questions, links to studies and hypothesis on my Facebook wall, I do now have a scientifically validated counterargument that could (theoretically ;-) shut the small nag up... for 3 full weeks!

6 Weeks on, 3 weeks off, 6 weeks on OR 15 weeks on - what is more "productive"?

Aside from the longer, more in-depth articles here at the SuppVersity, the studies, we are dealing with on a daily basis are usually not older than max. 4 weeks. In view of the fact that even "Prof. Dr.", i.e. me, is only human, it sometimes happens that I a) either miss the publication of an interesting paper or b) file it under "candidates" and then forget about it... the latter happened with a study, Steven referenced in a brief discussion we had on facebook about "priming muscles for new growth". Since the results do however fit in pretty nicely with the concept of "skeletal muscle hypertrophy" I have been trying to establish in the course of the latest installments of the Intermittent Thoughts (yes, there will be a follow up on testosterone tomorrow ;-), I decided that it was about time to finally acknowledge the results of a May 2011 paper by Riki Ogasawara et al. (Ogasawara. 2011).

In their 15-week randomized trial, Ogasawara and his colleagues put 15 young (24.7y), previously untrained male subjects onto identical training regimen. In three supervised training sessions per week the subjects performed 3 sets of 10 reps at 70% of their predetermined 1-RM max. The latter was re-assessed every three weeks and the weight was adjusted appropriately. After 6 weeks of training 8 randomly selected subjects "had" to take 3 weeks off (retraining group), while the rest of the subjects kept their regular 3x per week training schedule (continuous group). At the beginning of week 9, the now "detrained" subjects resumed their training regimen, until after week 15, a final testing session was scheduled to provide the data we need to answer a question, of which I know that it already preys on your minds:  "Did the three weeks away from the gym compromise the progress in the retraining group?" 

Figure 1: Development of triceps brachii and pectoralis major CSA of the continuously training and the detraining/retraining group in the course of the 15-week study period (data adapted from Ogasawara. 2011)

If you take a cursory glance at the data in figure 1, the answer to this question must be "YES!" (I think I just heard the little man in my ear rejoice ;-) - there is no debating: the triceps cross-sectional area (CSA) of the continuous trainers grew 2.4% more, the pectoralis major even 5.7% more, but with the given standard deviations of >7% and >10%, the little man in my ear will be having a hard time to convince me that I would miss out on muscle gains, when I took three weeks of - and that, even if I were a bloody beginner.

If we now assume that with my reluctance to take even a complete week off, my size gains would already have reached the "quasi-plateau" that is situated to the right of the logarithmic graph which describes the CSA development of the continuous training group, one could even make an argument that I and any other advanced trainee, whose gains have been slowing down over the last couple of weeks, would see an even more profound "growth boost" after 3 weeks of detraining, than the previously untrained subjects in the Ogasawara study. In fact, the increase in the amount of muscle mass I  would be able to accrue per week, might not only compensate (within the statistical margin ;-), but rather surpass the gains I thought I constantly fear I could "miss" during my off time.

Figure 2: Development of bench press 1RM strength and triceps brachii maximum voluntary contractive force of the continuously training and the detraining/retraining group in the course of the 15-week study period (data adapted from Ogasawara. 2011)

Moreover, the fact that the strength gains, in general, and the maximum voluntary contractile force the subjects were able to apply to a Biodex dynamometer with their elbow extensors, in particular, exhibit similar or even smaller differences (cf. figure 2), provide additional arguments by the means of  which I could probably convince myself that detraining is not for retiring athletes only.

Figure 3: Development of bench press 1RM strength (left) and triceps brachii maximum voluntary contractive force to triceps brachii CSA ratio (data adapted from Ogasawara. 2011)

And if that is still not enough to lay aside the dumb- and barbells for at least 2 weeks (you see I am negotiating again ;-), I could make a point that I do not only want to look strong, but also want to be strong; and as the right graph in figure 3 shows quite clearly, the three-weeks detraining period lead to 2.3% larger, yet again statistically non-significant increase in the pound per pound force production of the triceps muscle of the study participants in the retraining group.

Detraining is neither for pussies nor for retiring athletes, only

I guess, the foregoing subheading, summarizes the main take-away message of the study quite nicely. In view of the non-existent loss in muscle mass and strength in the course of the detraining period and the subsequent "growth spurt" (relative steep linear vs. leveled logarithmic increases in weeks 9-15), it should be obvious that the incorporation of strategic detraining periods into your training schedule is more than a welcome opportunity for laziness (something that totally turns me off, btw.). It is rather a phase where the reconstruction processes you have learned about in the Hypertrophy 101 and the subsequent installments of the Intermittent Thoughts will carve the way for future gains. Whether this will suffice to soothe the little man in your ear, I don't know... maybe you can negotiate a 2-weeks detraining period for the start ;-)