|Can't squeeze out another rep? Not a problem have some intra-set rest and continue pumping thereafter.|
Just like the regular show the live show will be kicking off at 1PM EST. If you miss it it's not a problem, there is also going to be a special edition of the "Seconds", tomorrow with Adelfo looking back at how the contest went and how he made sure to peak right on time (edit: you can download the podcast now).
And just to make sure that no one complains: I compiled a couple of news as a surrogate for the regular Science Round-Up, today (this was "last minute", so please ignore any typos and grammatical mistakes).
Rest-pause technique leads to greater strength w/ identical size gains (Oliver. 2012) -- The bad news first, I can't tell you exactly how long the 22 male subjects (25 +/- 5yrs, 179.71 +/- 5.0cm, 82.1 +/- 10.6kg, 13.6 +/- 4.3% fat, 6.5 +/- 4.5yrs training) Jonathan Oliver recruited for the experiment he wrote his dissertation on actually rested withing (=intra) their sets. Usually you would expect something along the 10 deep breaths - just enough to get your game on, so to say.
|Figure 1: 1-RM max and power on bench presses and squats before and after 12 weeks of classic (regular sets) and alternative intra-set rest interval (rest-pause) training in 22 young resistance trainees with >2y of training experience (Oliver. 2012)|
Dietary variety does not protect us from from becoming fat (Vadiveloo. 2013) -- In a soon-to-be-published systematic review of epidemiological studies researchers from the Steinhardt School at the New York University report that dietary variety does not protect against obesity. In fact, the exact opposite can be the case if "your variety" is a variety of sugar + fat-laden junk foods. In that case you are even more likely to fall victim to the metabolic syndrome than someone who eats just Twinkies and does not switch to Dingdongs once in a while:
This is, allegedly not a really surprising finding, what may yet surprise you is that the scientists didn't find a positive association for a variety of healthy foods in the diet, either. Sounds like quality and quantity, but not diversity remain what determines our likelihood of becoming obese... but let's be honest, isn't eating - at least from time to time - so much more than just providing your body with the nutrients it needs?
"The present review is an important first step in clarifying the associations between dietary variety and excess adiposity, which is currently limited by the methods used to assess variety.
If you are interested in buying quality, you may want to revisit the post on pesticide residues in organic and regular produce (go back)
In the present review, we found that (1) dietary variety within recommended and low-energy foods alone do not increase the odds of overweight and obesity, (2) greater variety within less healthful, energy-dense foods increases the odds of overweight and obesity and (3) the association between total dietary variety and adiposity is mixed and accurate evaluation of this association requires a consistent and theoretically valid measurement tool."
There is no protein synthesis without catabolism (Bentzinger. 2013) -- A very intriguing study that's about to be published in the next issue of Skeletal Muscle found that the constant and isolated expression of MTOR-1C in a rodent model leads to profound muscle catabolism and not as you may have expected exuberant muscle growth. The underlying reasons for this counter-intuitive effects are the m-TOR induced blockade of the p-AKT pathway which is also responsible of keeping the catabolic MuRF1 pathway in check:
In view of the fact that few of you will be mutants with a constant (over-)expression of mTOR-1C the scientists most recent observation does actually have implications for you as a trainee. It does not only re-emphasize the importance of the cyclic nature and tight inter-regulation of protein synthesis and degradation, but should also remind you no to rely too heavily on studies measuring only increases in protein synthesis without accounting for the net protein retention.
"Our study shows that the mTORC1- and the PKB/Akt-FoxO pathways are tightly interconnected and differentially regulated depending on the muscle type. These results indicate that long-term activation of the mTORC1 signaling axis is not a therapeutic option to promote muscle growth because of its strong feedback induction of the E3 ubiquitin ligases involved in protein degradation."
The AMPK-mTOR seesaw
GABA exerts indirect "anabolic" effects on the brain (Thanapreedawat. 2013) -- In yet another advanced publication that happens to overlap with the sudden re-appearance of GABA supplementation within the health and fitness community, Thanapreedawat and colleagues report that the administration of gamma-amino-butyric in the drinking water (0.5% and 1.0%) of young rats lead to highly significant activation of the intra-cerebral mTOR pathway, a subsequent dose-dependent increase in S6K1 phosphorylation and corresponding increases in brain protein synthesis.
|Figure 2: Relative changes (compared to control) in insulin, insulin-like growth factor (IGF-1) and growth hormone (GH) in response to 0.5% or 1.0% GABA in the drinking water of 3-week old Wistar rats (Thanapreedawat. 2013)|
The peripheral effects of the orally administered GABA, namely the pronounced increase in growth hormone (GH) (cf. figure 2), a molecule which has previously been shown to be able to cross the blood brain barrier (Bermann. 1994; Ohsumi. 2008) lead to an activation of the intra-cerebral mTOR cascade and the subsequent increase in protein synthesis. If you expand on that, you could even speculate about other GH mediated effect of GABA supplementation... I must yet forewarn you: GABA is not a proven ergogenic of any kind (doesn't build muscle, doesn't make you lean, etc.).
Usually this would be the place to add some references to the latest Facebook news, but since the show is about to start in a couple of minutes (listen live), I'll just refer you directly to the SuppVersity Facebook Wall. With 6-9 studies you won't read about anywhere else every day, it's always worth visiting, anyway ;-)
- Bentzinger CF, Lin S, Romanino K, Castets P, Guridi M, Summermatter S, Handschin C, Tintignac LA, Hall MN, Rüegg MA. Differential response of skeletal muscles to mTORC1 signaling during atrophy and hypertrophy. Skelet Muscle. 2013 Mar 6;3(1):6.
- Bermann M, Jaffe CA, Tsai W, DeMott-Friberg R, Barkan AL. Negative feedback regulation of pulsatile growth hormone secretion by insulin-like growth factor I. Involvement of hypothalamic somatostatin. J Clin Invest. 1994 Jul;94(1):138-45.
- Ohsumi M, Tujioka K, Hayase K, Nagata S, Yokogoshi H. The growth hormone affects the brain protein synthesis rate in hypophysectomized aged rats. J Nutr Sci Vitaminol (Tokyo). 2008 Feb;54(1):76-81.
- Oliver J. Intra-Set Rest Intervals in Hypertrophic Training: Effects on Hypertrophy, Strength, Power, and Myosin Heavy Chain Composition.Doctoral dissertation, Texas A&M University. 2012.
- Thanapreedawat P, Ohsumi M, Hayase K, Yoshizawa F, Yokogoshi H. Influence of GABA on Brain Protein Synthesis Mediated by the Mammalian Target on the Rapamycin Pathway. Biosci Biotechnol Biochem. 2013 Mar 7.
- Vadiveloo M, Dixon LB, Parekh N. Associations between dietary variety and measures of body adiposity: a systematic review of epidemiological studies. Br J Nutr. 2013 Feb 27:1-16.