Day 4 of the Exercise Science Week - A Double Dose of HIIT vs. Steady State Aerobics
(Cocks. 2012 & Shephard. 2012) -- If you ignored the titles and just read the first part of the methodological section it seems as if the two studies that were subsequently published in The Journal of Physiology late in 2012 were identical. What's identical, though is just the data set the two papers by scientists from the University of Birmingham are based on. The latter was acquired during a six-week experiment in the course of which 16 previously sedentary young men (BMI ~23kg/m²; age 21.5y) were randomized to a
classic steady state endurance training regimen - subjects cycled at workloads equivalent to ∼65% of their pre-established VO2peak for 40min in the first 2weeks, increasing to50min in the following 2 weeks, and 60min in the final 2 weeks; their obviously improved VO2peak was reassessed after 3weeks of training and workload adjusted accordingly34% increase in time to exhaustion, +91% increase in total work & exponentiated lean mass gains in response to HIIT + NAHCO3 (read more)
- sprint interval training - subjects performed 30s "all out" (Wingate test) on a cycle ergometer using a load equivalent to 0.075kg per kg of body weight; each of the Wingate tests was followed by a period of 4.5 min of recoery (at 30W; <50rpm); the number of sprints increased from 4 to 6 sprints with one additional sprint every 2 weeks
Figure 1: Overview of the relative changes of selected outcome variables measured in the "two" studies (Cocks. 2012; Shephard. 2012) |
More similarities than differences?!
Figure 2: Selected parameters of body composition and blood glucose metabolism expressed relative to pre-exercise levels. (Shephard. 2012) |
Despite this difference, the usage of intramuscular triglycerides (IMTGs) during exercise was increased after both trials:
"In comparison to pre-training, net IMTG break- down in type I fibres was significantly greater following training (training×time interaction; P<0.05), with no difference in net IMTG breakdown between groups. Both pre- and post-training, the reduction in IMTG content in type I fibres was attributed to decreases in IMTG density after SIT (pre-training, 21±13%; post-training, 38±7%) and ET (pre-training, 20±17%; post-training, 32±8%)." (Shephard. 2012)The greater increase in IMTG response to exercise in the SIT (HIIT) group appears to be in line with the previously mentioned role of perilipin 5 (PLIN5) as a driving force of intracellular muscle triglyceride mobilization. After all, the PLIN5 expression of the interval training group increased to a significantly greater degree than the one of the endurance training group. A subsequent correlation analysis confirmed strong associations of PLIN2 und PLIN5 with IMTG breakdown and modest associations with muscular insulin sensitivity.
Para- vs. sympathetic overtraining: I would venture the guess that most of you will think of performance decrements, fatigue, depression, increased sleeping needs, constant weight or even fat gain, and lowered heart rate, i.e. the characteristic symptoms of parasympathetic (=addisonoid) overtraining, whenever they hear or read the term "overtraining". Its evil sympathetic twin, which is also known as basedowoid overtraining (named after morbus basedow) and likewise associated with performance decrements and fatigue yet in combination with an almost stimulant like restlessness, disturbed sleeping patterns, weight loss, and accelerated heart rate, is yet way less know. So, if you wake up in the middle of the night sweating like a pig and with a heart rate similar to the one you had during your last HIIT session, you better cut back on the weight lifting and HIIT side of your regimen - w/out necessary increasing the aerobics, though.
Bottom line: If you combine these mechanistic insights, with the main outcomes of the Cocks paper, which found ET and SIT "equally effective at decreasing arterial stiffness and increasing skeletal muscle capillarisation and eNOS content", even HIIT (or SIT, as it's called here) haters will be hard pressed to argue with Shephard et al.'s conclusion that.."[d]espite the large differences in duration and energy expenditure between SIT and ET, we provide novel evidence indicating that SIT induces similar improvements [in almost all measured parameters and] provides a time-efficient exercise alternative to achieve improvements in aerobic fitness and insulin sensitivity." (Shephard. 2012)So, now it's up to you 3x per week HIIT or 5x per week SIT? The answer appears to be clear, however, for people who are also strength training on a higher volume / density regimen, the addition of only 2-3 low(er) intensity aerobic sessions may still be the "safer" alternative in order not to overtax the sympathetic nervous system and keep a balance between sympathetic and parasympathetic activation in your routine.
More, really short news
Put introduction here- Hazelnuts: A polyphenolic "superfood" that's prebiotic by nature (Montella. 2013) -- The skin of hazelnuts has only recently been identified as "one of the richest edible sources of polyphenolic compounds" - a polyphenol source that can compete with green tea and coffee, by the way (Clani. 2012).
In a paper that's soon going to be published in Food Chemistry researchers from the Italy and the United States report that the skin does also contain a whole host of potent pre-biotics:Hazelnut peel is laden with gut friendly prebiotics & antioxidant plyphenols "Over thirty complex free oligosaccharides, composed mainly of galacturonic acid and N-acetylgalactosamine, were characterized for the first time in the present study. Their concentration ranged between 16 mg and 34 mg per g of extract." (Montella. 2013)
And if you find that unfair, because you are allergic, you may be interested in a 2005 paper by Enrique et al. who found that their sublingual immunotherapy for hazelnut food allergy worked quite well in a first randomized, double-blind, placebo-controlled study with a standardized hazelnut extract (Enrique. 2005)
"Eat your mushrooms!" mothers are probably saying that not often enough (Kalogeropoulus. 2013; Ma. 2013) -- According to a recent study by Nick Kalogeropoulus et al. all five five wild edible mushrooms species (Lactarius deliciosus, Lactarius sanguifluus, Lactarius semisanguifluus, Russula delica, Suillus bellinii) from Lesvos Island, the researchers recently analyzed in their laboratory contained significant amounts of polyphenols, with the more abundant ones being p-OH-benzoic acid, p-OH-phenylacetic acid, o-coumaric acid, ferulic acid and chrysin. Moroever, the Greek scientists were also able to isolate the riterpenic acids oleanolic and ursolic acid (yeah, that stuff that's currently sold as test booster).Inonotus obliquus (chaga mushroom) does actually looks like a tumor, but contains compounds that have the ability to kill prostate and breast cancer cells (photo by Tomas Čekanavičius)
If you add to that the not even published results of Ma, Chen, Dong and Lu, who fount that the ergosterol, ergosterol peroxide and trametenolic acid in Inonotus obliquus (chaga mushroom), another mushroom that has been used in TCM for centuries, do not only have potent anti-oxidant activity, but can also kill human prostate and breast cancer cells, the initially raised question, why your mother never told you to "eat your mushrooms" suddenly appears in a very different light, doesn't it?
- Did you know that the aggregate-accessory fruit (with the green dots on its flesh being its "nuts") has the highest total antioxidant capacity, when it's still green (see facebook news), can contain up to 160mg/g of fisetin (Kimira. 1998) and that the latter has been shown to reduce thyroid peroxidase activity (Divi. 1996) and thus to protect against thyroid cancer? Fisetin is also supposed to have anti-allergic and anti-angiogenic (pro - cardiovascular health) effects.Strawberry polyphenol fisetin ameliorates hepatic steatosis and lowers circulating glucose concentrations (Cho. 2013) -- While it's still a couple of days until the Strawberry season will begin it's still good to know in time that the fisetin content in strawberries can ameliorate hepatic steatosis and decrease blood glucose levels by increasing GLUT-4 (glucose transporter 4) expression in a rodent model of diet induced obesity.
Unfortunately, the changes the Korean scientists observed in response to a human equivalent dose of 130mg/day was statistically significant yet not uniquely impressive and "thanks" to the increase in PPAR-gamma and the non-selective increase in GLUT-4 receptor expression (measured only on adipocytes), the rodents in the supplemented group got exactly as obese as their unsupplemented pears. Nevertheless, better "weighty" and healthy than skinny fat and sick, right?
- Scientists find alternative androgen pathway - DHT synthesis from progestorone more effective than from testosterone (Kamrath. 2013) -- Usually it's my friend Carl Lanore who says that he, respectively Super Human Radio has the smartest listeners. I would hovewer argue that listening is easier than reading the stuff I produce (including sentences that are longer than the paragraphs of most other bloggers) and therefore it's no wonder that SuppVersity readers must be at least as smart ;-)
That being said, I just received a facebook message from Rob, who pointed me towards a very recent paper claiming that there was an "alternative androgen synthesis pathway" in human beings. "Alternative pathway?" Sounds like the adrenal gland and the DHEA => Testosterone => DHT pathway, right? That's what I thought, as well, but actually this one is different. As the pediatric scientists from the JLU Gießen (Germany) point out in their review of the literature, there is a hitherto largely overlooked "backdoor" by the means of which 17α-hydroxyprogesteron instead of it's 12,30 lyase product androstendione is 5α-reduced to 17α-hydroxy-dihydroprogesteron, which is then, in a 4-step process converted to 17α-hydroxyallopregnanolon (2α-HSD), Androsteron (12,20-Lyase), androstandiol (17b-HSD) and finally DHT (3α-HSD).The alternative pathway to androgen (DHT) synthesis as proposed by Kamrath et al. "This so-called "backdoor" synthesis pathway appears to play an important role especially during the development of male fetuses, since respective defects will result in a suppressed virilization in boys." (Kamrath. 2013)
Another context that's probably more important for most of you is the role of the "backdoor" in castrate (and probably also androgen suppression) resistant prostate cancer, where this alternative pathway jumps in, when the regulate substrate for DHT synthesis by a mere change in the specific 5α-reductase subtypes.
Now don't tell me you still haven't had enough for today? I mean, with the long article on the sprint vs. endurance study you've just gotten day 4 of the SuppVersity Exercise Science Week, and with the other short notice items, even those of you who have been missing nutrition and other news within the past couple of days should have gotten way more than your money's worth - after all, the SuppVersity is still free!
Since the same also goes for the facebook news, I'd suggest you head over to the SuppVersity Facebook Wall, where you will find roughly half a dozen of additional short news items every day. Examples? This is a selection of what you could already have known if you were already a friend, fan or whatever you call that on facebook, when you click on the "like button" at www.facebook.com/SuppVersity:
Since the same also goes for the facebook news, I'd suggest you head over to the SuppVersity Facebook Wall, where you will find roughly half a dozen of additional short news items every day. Examples? This is a selection of what you could already have known if you were already a friend, fan or whatever you call that on facebook, when you click on the "like button" at www.facebook.com/SuppVersity:
- Skin protection from within - Orally ingested green tea or rather respective catechin metabolites end up in your skin and protects it from UV radiation (read more)
- Iron deficiency starts in the gut - Epidemiological findings confirm: Even people with mild gastrointestinal inflammatory bowel disease need more iron and co-factors in their diet to prevent deficiency than healthy individuals (read more)
- Hormonal contraception increases risk of HIV infection - Medroxyprogesterone acetate (MPA) suppresses both innate and adaptive arms of the immune system resulting in a reduction of host resistance to invading pathogens (read more)
- Grape seed and peel extracts stop working, when they are "purified" - Another case where man shalt not isolate what nature put together, if he wants to have the active ingredients survive the digestive process (read more)
Just out: Part II of my interview with Sean Casey. This time about the A-Z of supplements for strength, endurance and all other trainees who want to boost their health and performance (read more) |
References:
- Calani L, Dall'Asta M, Derlindati E, Scazzina F, Bruni R, Del Rio D. Colonic metabolism of polyphenols from coffee, green tea, and hazelnut skins. J Clin Gastroenterol. 2012 Oct;46 Suppl:S95-9.
- Cocks M, Shaw CS, Shepherd SO, Fisher J, Ranasinghe AM, Barker TA, Tipton KD, Wagenmakers AJ. High intensity interval and endurance training are equally effective in increasing muscle microvascular density and eNOS content in sedentary males. J Physiol. 2012 Sep 3.
- Divi RL, Doerge DR. Inhibition of thyroid peroxidase by dietary flavonoids. Chem Res Toxicol. 1996 Jan-Feb;9(1):16-23.
- Enrique E, Pineda F, Malek T, Bartra J, Basagaña M, Tella R, Castelló JV, Alonso R, de Mateo JA, Cerdá-Trias T, San Miguel-Moncín Mdel M, Monzón S, García M, Palacios R, Cisteró-Bahíma A. Sublingual immunotherapy for hazelnut food allergy: a randomized, double-blind, placebo-controlled study with a standardized hazelnut extract. J Allergy Clin Immunol. 2005 Nov;116(5):1073-9.
- Kalogeropoulos N, Yanni AE, Koutrotsios G, Aloupi M. Bioactive microconstituents and antioxidant properties of wild edible mushrooms from the island of Lesvos, Greece. Food Chem Toxicol. 2013 Jan 24.
- Kamrath C, Hartmann MF, Wudy S. The alternative androgen synthesis pathway in humans. Klin Padiatr. 2013 Jan;225(1):3-7. [Article in German]
- Kimira M, Arai Y, Shimoi K, Watanabe S. Japanese Intake of flavonoids and isoflavonoids from foods Journal of Epidemiology. 1998; 8:168–175.
- Ma L, Chen H, Dong P, Lu X. Anti-inflammatory and anticancer activities of extracts and compounds from the mushroom Inonotus obliquus Food Chemistry. Feb 2013 [in press]
- Montella R, Coïsson JD, Travaglia F, Locatelli M, Bordiga M, Meyrand M, Barile D, Arlorio M.dentification and Characterization of Water and Alkali Soluble Oligosaccharides from Hazelnut Skin (Corylus avellana L.) Food Chemistry. Feb 2013 [in press]
- Shepherd SO, Cocks M, Tipton KD, Ranasinghe AM, Barker TA, Burniston JG, Wagenmakers AJ, Shaw CS. Sprint interval and traditional endurance training increase net intramuscular triglyceride breakdown and expression of perilipin 2 and 5. J Physiol. 2012 Dec 17.
- Thvilum M, Brandt F, Almind D, Christensen K, Hegedüs L, Brix TH. Excess Mortality in Patients Diagnosed With Hypothyroidism: A Nationwide Cohort Study of Singletons and Twins. J Clin Endocrinol Metab. 2013 Jan 30.
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