Sabtu, 30 April 2016

Cholesterol Boosts Your Immune Defenses: Infections Can Lower Cholesterol, Extra-Chol. Will Help You Battle Them

Health food for sick people - Much better than cholesterol supplements ;-)
Cholesterol is the villain of the 20th century. In the 21st century, however, the evidence that vilifying the building-block of hormones and cell membranes has more negative than positive consequences is accumulating.

The latest piece to the pro-cholesterol puzzle is a study from the Capital Medical University (Wang. 2016) in Beijing, China. A study in which the researchers tried to get to the bottom of the proven link between cholesterol and several adverse outcomes in various disesase - especially infectious ones.
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The authors conducted a study to supplement cholesterol, and observe the change on the test indexes and the severity of disease. Their randomized and controlled clinical trial was conducted at the infectious disease department in Beijing Friendship Hospital, Capital Medical University, Beijing, between January 2011 and December 2012.

The subjects were hospitalized patients with pulmonary infection, patients who were assigned into intervention group and control group randomly and subsequently received a 10-day course of either
  • extra 600mg cholesterol per day (provided by the egg yolk) or 
  • a placebo supplement devoid of cholesterol, but w/ the equivalent amount of vitamin A
to see how the extra cholesterol would affect the course of the subjects' illnesses. In that, the extra-vitamin-A in the control group is crucial, because of retinols paramount importance in the immune response to infections (Glasziou. 1993; Semba. 1994 | see Figure 1):
Figure 1: Effects of vitamin A on the mortality outcomes of various illnesses (Glasziou. 1993).
In conjunction with the dietary standardization, which involved a protein intake standard of 1.0g/kg ideal body weight (50% high quality protein), a carbohydrate intake standard of 50-60% of the total energy intake (mostly complex carbohydrates) and a fa

t intake of below 30% of the predetermined optimal energy intake for each of the patients, the scientists tried to ensure that no external factors would interfere with the recovery of their hospitalized (=tightly controlled) patients.
Figure 2: Effects of treatment / placebo on total cholesterol and SAPSII scores (Wang. 2016).
And guess what? The scientists' statistical analysis of the differences on indexes between after 10-day intervention in intervention group and after 10-day observation in control group showd significant differences in seven indexes, total cholesterol (TC), Body Mass Index (BMI), albumine (ALB), pre-albumin (PA), CRP, IL-6 and, most importantly, the severity of disease.
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"The increased concentrations of TC, ALB and PA in intervention group were more than those changes in control group. The BMI in intervention group was increased more than that in control group.

The decreased concentrations of CRP and IL-6 in intervention group were more than those changes in control group. The improvement of severity of disease in intervention group was more obvious than that in control group. The improvement of nutrition status in intervention group was significant" (Wang. 2016).
Now, you can argue that all that may be due to other ingredients in the egg-yolk, but let's be honest: if infections, especially pneumonia and pulmonary infection disease, can lead to hypocholesterolemia and supplementation of cholesterol properly can improve the nutritional status, decrease the severity of disease, and improve the prognosis of disease, that's quite a convincing piece of evidence in favor of the importance of cholesterol in our bodies' fight against infections.
Bottom line: Yes, you can argue that cholesterol is a "vitamin" in infectious disease - a vitamin in the sense of a nutrient of which your body cannot produce enough on its own as a consequence of infections like pneumonia and pulmonary infection disease.

The yolk is where almost all the "good" stuff in the eggs resides. Throwing the yolk of the 1-2 eggs you eat per day away, as people have been doing it for decades is thus madness | more
I suspect that you will still share my doubts that increasing a patient's cholesterol will in fact become the "new therapeutic target" in the treatment of infection diseases - and that in spite of the fact that this kind of "treatment" could, as the authors point out, be of particular importance in the elderly, where, in clinical practice, doctors obviously "have not fully realized the impact of low cholesterol level" (Wang. 2016). Rather than to "consider [... a] cholesterol treatment for [their] patients" (ibid.), doctors will continue to administer statins and enteral nutrition solutions that are devoid of the amounts of cholesterol of which the study at hand shows that they are critical to support patients' (and probably athletes) immune systems | Comment!
 References:
  • Glasziou, P. P., and D. E. Mackerras. "Vitamin A supplementation in infectious diseases: a meta-analysis." Bmj 306.6874 (1993): 366-370.
  • Semba, Richard D. "Vitamin A, immunity, and infection." Clinical Infectious Diseases 19.3 (1994): 489-499.
  • Wang, Jia, and Zhong-xin Hong. "Cholesterol Supplement can Alleviate the Severity of Pulmonary Infection of Patients with Hypocholesterolemia." Journal of Food and Nutrition Research 4.3 (2016): 131-136.

Kamis, 28 April 2016

Breakdown aka Drop-Sets, Another Very Popular Advanced Training Technique W/Out Sign. Adaptational Advantages?!

"There are some crossovers between size training and strength training, and using drop-sets and ladder sets will definitely give some benefit ...," this is what you can read on the Internet, but is that true?
In view of the fact that resistance training (RT) leading to momentary muscular failure (MMF) has been evidenced as producing significantly greater muscular strength and hypertrophic adaptations when compared with RT not performed to MMF in various studies (Fisher. 2011 & 13), the assumption that techniques that promote the occurrence of MMF and the subsequent increased recruitment of motor units (MUs) and muscle fibers (Henneman’s size principle | Carpinelli. 2008; Jungblut. 2009) would produce increased muscular strength and size gains is only logical.

In spite of the existing evidence that training to MMF seems to be important for optimizing adaptations, the use of advanced RT techniques that allow a trainee to potentially train beyond failure, has yielded worse than 'mixed' results.
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The latter goes for techniques, such as rest-pause (Giessing. 2014) and pre-exhaustion (Fisher. 2015), as well as using supra-physiological loads - all of them didn't show the benefits scientists had hoped for based on their ability to train to full or eve past MMF.

In a recent study, Fisher et al. did now investigate another commonly used intensity / advanced training tequnite: breakdown (BD) aka  drop sets o descending (Ogborn. 2014; Ratamess. 2009).
"Breakdown sets require the performance of a set to MMF with a given load before immediately reducing the load and continuing repetitions to subsequent MMF. As such, this technique can allow MMF to be achieved in addition to potentially inducing greater fatigue-related stimuli. It is thought that this might maximize recruitment of both type II and type I MUs through use of both heavier and lighter loads thus allowing the combination of high muscular tension and inducing greater MU fatigue, metabolic stress, and ischemia because of extended time under tension" (Fisher. 2016).
In said study, the authors expected that reducing the load from set to set would allow those muscle fibers that have not reached a state of complete fatigue with higher loads to be eventually recruitment, as well. The expected consequence obviously is an augmentation of the subjects' adaptive response to exercise, one of which we have little scientific evidence, though:
"To date, there are few empirical research studies that have considered the use of BD training. Keogh et al. (24) and Goto et al. (2003) considered the acute effects of BD training on muscle activation and hormonal response, respectively. However, neither study provides evidence toward chronic adaptations. Goto et al. reported greater increases in growth hormone (GH) after the BD training protocol (sets of knee extension at 90% 1RM followed by a set at 50% 1RM) compared with a traditional RT protocol (sets of knee extension at 90% 1RM)" (Fisher. 2016).
Since Keogh et al. (24) used a variation of BD training whereby participants only performed a single repetition at a near-maximal load (95% 1RM) or starting with the 1RM as it was done in the Berger and Hardage study before reducing the load for each of 5 consecutive repetitions, the significance of their results for anyone doing "regular" drop sets / BD sets.

Figure 1: Strength and size gains with regular training (HS) and regular training plus a single set of low-intensity high rep RT after 5 high intensity, low rep sets (Goto. 2004).
A more realistic study was conducted by Goto et al. in 2004. In said study, the participants performed 6 weeks of an identical resistance exercise protocol and were then divided into either BD or traditional training groups. The traditional training group performed 5 sets of knee extension and leg press exercise 2 times per week at 90% 1RM with 3 minutes rest between exercise sets. The BD
training group performed the same protocol with an additional set performed 30 seconds after the fifth sets using 50% 1RM, where all sets in both groups were continued to a point of MMF.

The authors reported significantly greater results for leg press 1RM and maximal isokinetic torque (300 degree per second) and muscular endurance (repetitions to MMF at 30% of maximal voluntary contraction [MVC]) for the knee extension for the BD protocol compared with the traditional protocol.
SuppVersity Suggested (read more).
SuppVersity Suggested: "Training to Failure and Modifying Rest Times: Two Ways to Maximize Muscle Activity? Two Studies, Similar Implications" (read more). In a previous SuppVersity feature article, I have addressed not one, but two potentially highly relevant articles from the Journal of Strength and Conditioning Research (Looney. 2015) and the European Journal of Sport Science (Hiscock. 2015). What makes these papers interesting is that they tested the effect of commonly prescribed remedies to "bust a plateaus": (a) Training to failure and (b) modifying rep schemes and whether you fail or don't fail on every set.
However, as Fisher et al. point out, the "authors reported that the BD group showed greater increases in muscle cross-sectional area (CSA) of the thigh compared with the traditional group; however, this did not reach significance (p , 0.08)" (Fisher. 2016) - a non-significant advantage with a training protocol with higher volume? That's not exactly convincing, right?

The new study - What does it add to the existing research?

Therefore, Fisher et al. did another study with a randomized controlled trial design was adopted, with 3 experimental groups included. The effects of 3 RT interventions were examined in trained participants upon muscular performance and body composition.
Figure 2: Consort diagram showing how the study was designed (Fisher. 2016)
Participants were required to have had at least 6 months of RT experience (single-set training to MMF for multiple exercises including most major muscle groups, >2 times per week) and no medical condition for which RT is contraindicated to participate. Participants were then randomized using a computer randomization program to 1 of 3 groups: regular BD aka drop set training (n = 11), heavy-load breakdown (HLBD, n = 14), and  a control (CON, n = 11) group.
Putting the results into perspective: Every study has its strengths and weaknesses. For the study at hand, for example, the repetition volume standardization is both, a strength and a weakness: While it is meant to effectively isolates the effects of breakdown / dropsets (you can argue that it failed, because the total volume as reps x weight still differed, albeit not significantly), you could argue that doing more reps is what doing dropsets is all about. As the scientists point out, the mixed gender of the study population, and its uneven distribution across the three groups, as well as the low number of exercises and exercise-specific benefits (for the chest press the statistical analysis revealed p = 0.051, with effect sizes differing considerably between BD, HLBD, and CON groups - 1.22, 2.74, and 1.46, respectively) are other factors that may warrant further investigation in differently designed studies, before we can finally confirm that dropsets are another useless advanced training technique.
Participants were asked to refrain from any exercise away from the supervised sessions. Body composition was estimated using air displacement plethysmography (Bod Pod GS; Cosmed, Chicago, IL, USA) before and after working out twice per week for 12 weeks according to a protocol, Fisher et al. describe as follows:
"Each exercise was performed for one set (+ breakdown set in the BD group) per training session at a 2:4 repetition duration until MMF (i.e., when they reached a point of concentric failure during a repetition) to control for intensity of effort between groups. All participants performed 2 exercise sessions per week. The first of these, workout “A,” consisted of chest press, leg press, pull-down (MedX) overhead press, adductor, abductor (Nautilus Evo, Vancouver, WA, USA), abdominal flexion (MedX Core Ab Isolator), and lumbar extension (Roman chair using bodyweight or manual resistance; Hammer Strength, Rosemount, IL, USA). The second session, workout “B,” consisted of pecfly, pullover (Nautilus Evo), leg extension (MedX), dip, biceps curl (Nautilus Evo), seated calf raise (Hammer Strength), leg curl, and core torso rotation (MedX) resistance machines" (Fisher. 2016).
As usual, the weights were increased by 5%, once participants were able to perform more than 12 repetitions before achieving MMF.  The breakdown / dropsets were used for the chest press, leg press, and pulldown exercises in workout A only (e.g., the exercises that were tested). All other exercises were performed to MMF with a load permitting 8–12 repetitions.
  • BD group: For the chest press, leg press, and pull-down exercises, the BD group performed a single set of 8–12 repetitions to MMF and immediately reduced the load by ~30% and then continued performing repetitions to MMF. 
  • HLBD group: Using the same 3 exercises, the HLBD group used a heavier load permitting only ~4 repetitions; upon reaching MMF, they decreased the load by ~20% and continued performing repetitions to MMF and then repeated the BD reducing the load by a further 20% and performing repetitions to MMF. 
  • CON group: Subjects in the control group performed all exercises for a single set of 8–12 repetitions to MMF with no BD. 
As Fisher et al. point out, the "group protocols were chosen to allow parity between training load (the BD and CON groups both used the same relative load to begin; permitting 8–12 repetitions) and repetition volume (the HLBD and CON groups both performed a total of ~8 to 12 repetitions)" (Fisher. 2016)... and guess what: With identical load and repetition volume, the scientists found "no significant between-group [pre vs. post] differences" (Fisher. 2016) for change in absolute muscular
endurance for chest press, leg press, or pull-down exercises or for body composition changes.
Figure 3: Looking at the error bars will suffice to tell that there was no significant inter-group difference (Fisher. 2016).
In line with that, the effect sizes for absolute muscular endurance changes were large for all groups and exercises (0.86–2.74) - again, whithout significant inter-group differences.
Bottom line: As the authors point out, "[t]he present study supports previous research that the use of advanced training techniques stimulates no greater muscular adaptations when compared with
performing more simplified RT protocols to momentary muscular failure" (Fisher. 2016).

While the set volume was identical, the total volume (weight x reps) differed, albeit non-significantly, in favor of HLBD and CON (Fisher. 2016).
This is a hardly debatable result, but it may still be misleading: After all, the same standardization of initial loads and the repetition volume that is necessary to get reliable scientific information about the effects of dropsets / breakdown sets on their own, fails to represent the reason and effects of / for using drop sets in the real world: an increase in set volume (not total volume = weight x reps, see Figure to the right). Overall, it is thus not impossible that you may see the same improvements, Goto et al. observed in the previously discussed 2004 study. Eventually, however, this may be a result of an increased set volume, not the often talked about funky increase in muscle fiber recruitement | Comment on Facebook!
References:
  • Fisher, James, et al. "Evidence-based resistance training recommendations." Med Sport 15.3 (2011): 147-162.
  • Fisher, James, James Steele, and Dave Smith. "Evidence-based resistance training recommendations for muscular hypertrophy." Med Sport 17.4 (2013): 217-235.
  • Fisher, James Peter, et al. "The effects of pre-exhaustion, exercise order, and rest intervals in a full-body resistance training intervention." Applied Physiology, Nutrition, and Metabolism 39.11 (2014): 1265-1270.
  • Fisher, James Peter, et al. "The effects of breakdown set resistance training on muscular performance and body." (2015).
  • Giessing, Jürgen, et al. "The effects of low volume resistance training with and without advanced techniques in trained participants." J Sports Med Phys Fitness. Epub (2014).
  • Goto, Kazushige, et al. "Muscular adaptations to combinations of high-and low-intensity resistance exercises." The Journal of Strength & Conditioning Research 18.4 (2004): 730-737.
  • Ogborn, Dan, and Brad J. Schoenfeld. "The role of fiber types in muscle hypertrophy: Implications for loading strategies." Strength & Conditioning Journal 36.2 (2014): 20-25.
  • Ratamess, N. A., et al. "Progression models in resistance training for healthy adults [ACSM position stand]." Med Sci Sports Exerc 41.3 (2009): 687-708.
  • Sandee, Jungblut. "The correct interpretation of the size principle and it’s practical application to resistance training." Med Sport 13 (2009): 203-209.

Selasa, 26 April 2016

Baking Bread With ~100g Extra-Fat Reduces the Glycemic Response: Coconut Oil Beats Butter, Grapeseed & Olive Oil

No, adding fat to your bread's dough won't make you lose fat magically.
While fat no longer has the bad rep it still had a decade ago, the notion that baking bread with extra fat could have anti-diabetic effects, because it reduces the glucose peaks and the 2h area under the curve (AUC) is unconventional, to say the least; and thus SuppVersity news-worthy, because it is not broscience, but the result of a recent study.

In said study, the scientists tested (a) the effect of different types of fat / oil on the formation of amylose–lipid complexes (ALC) and, more importantly, (b) the effect of the ALCs on the glycemic response to a standardized amount of bread that was baked with the same amount of different fats / oils.
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The study was an acute, randomised, controlled, single-blinded trial that consisted of five types of bread, each tested on one occasion in a randomised order on separate days, with at least 3 washout days between test visits.
"Participants were recruited through advertisements and personal communications. Inclusion criteria were as follows: (1) males aged between 21 and 50 years, (2) BMI values between 18·0 and 24·9 kg/m2, (3) blood pressure≤120/80 mg/dl and (4) fasting blood glucose≤6·0 mmol/l. People who had metabolic diseases, were on prescribed medication, were smokers, took part in sports at competitive levels or were concurrently participating in other clinical trials were excluded from the study. Females were excluded from the study to prevent differences in menstrual cycles from affecting carbohydrate metabolism" (Lau. 2016).
On the day before a test session, no drinks, caffeine or physical activity were allowed. In addition, a standardised dinner was provided the evening before to reduce potential variations in GR that may arise because of the second meal effect. On the day after, participants had to report to the centre after a 10–12 h fast between 08.00 and 09.00 hours. There, they rested for at least 15 min before starting the test session, before the test meal was consumed "at a comfortable pace within 15 min" (Lau. 2016). Following consumption of test bread, participants were asked to rate their liking of the bread on a 100-mm liking scale. Blood samples (both venous and capillary) were collected at 15, 30, 45, 60, 90, 120, 150 and 180 min after test bread consumption. The same protocol was repeated until the completion of all the five test sessions.
Serving size, energy content and macronutrient composition of the test breads (per serving | Lau. 2016)
How was the bread prepared? This is what the scientists report: "The five types of bread used were as follows: control bread without any added fats (CTR) and breads baked with butter (BTR), coconut oil (COC), grapeseed oil (GRP) or olive oil (OLV). The ingredients used for test breads were as follows: 250 g bread flour (Prima), 125 g potable water, 10 g baker’s yeast (SAF), 40 g sugar (Fairprice) and 6 g salt (Fairprice). These ingredients were mixed at speed 1 for 8 min (Kitchenaid) to form base dough, of which 320 g was weighed and then fat/oil was added.

The fats/oils added were 96 g butter that contained predominantly SFA (Anchor), 87 g coconut oil that was rich in medium-chain TAG (Titi Ecofarm), 80 g grapeseed oil containing predominantly PUFA (Borges) and 76 g olive oil containing predominantly MUFA (Naturel). The amount of fats/oils added was calculated based on the percentage fat as stated on the nutritional panel on the packaging, and was added at 20 %, w/w of dough. Oil was not added into the control bread. The dough mixture was kneaded for a further 12 min, and was then allowed to rest at room temperature for 10 min. Following this, the dough was moulded into serving portions and proofed in the oven (EOB98000; Electrolux) at 40±1°C for 30 min in a fan-assisted mode. Baking was carried out in the same oven at 200°C for 18 min, and bread was allowed to stand for 10 min before being served warm" (Lau. 2016).
The results of the scientists' analysis of the ALC formation in the bread showed that the coconut (COC) and olive oil (OLV) had significantly higher amylose–lipid complex forming ability [reported wrong in the result section of the FT, but correct in the discussion] as compared with butter (BTR) and grapeseed oil (GRP | P<0·05).
Figure 1: Complexing index results for different types of bread. Values are means (n 6), with standard errors represented by vertical bars. a,b Mean values with unlike letters were significantly different (P < 0·05; one-way ANOVA with post hoc Tukey’s test). BTR = butter; COC = coconut oil; GRP = grapeseed oil; OLV = olive oil (Lau. 2016).
Interestingly, the increased ALC levels in the olive oil bread did not produce the same beneficial effects on the glucose response the scientists observed when the subjects consumed the bread that was baked with coconut oil.
Figure 2: (a) Postprandial response curves for change in blood glucose and (b) plasma insulin levels after consumption of 50 g available carbohydrate portion of test bread. Values are means (n 15), with standard errors represented by vertical bars. For glucose response, there were significant time (P < 0·001), bread (P < 0·001) and bread×time interaction effects (P=0·002) when analysed by two-way, repeated-measures ANOVA. For insulin response, two-way, repeated-measures ANOVA showed a significant time effect (P < 0·001) and bread×time interaction effect at near significant levels (P=0·074), but no effect of bread was seen (P=0·195). open circle, Control bread without oil; filled circle, bread with butter; open triangle, bread with coconut oil; filled triangle, bread with grapeseed oil; open square, bread with olive oil (Lau. 2016).
As you can see in Figure 2, all fat-enhanced breads improved the glycemia, but only the grapeseed (closed triangle) and coconut (open triangle) oils also rduced the insulin levels.
Can't I just add the coconut oil on top of the bread? No, you can't, because it has to be in the dough during baking - otherwise the amylose–lipid complexes won't form. What will happen though is that your insulin levels will rise sign. longer (see previous SV article). Edit: Elizabeth Alcott just posted this cool suggestion on Facebook: "Bake low carb coconut flour bread with coconut oil. Reduced calories and glycemic response at the same time." Not a bad idea, for sure.
What is interesting to see, though, is that the glucose AUC, i.e. the total amount of glucose that is released into the blood was still the lowest in those oils / fats with the highest ALC levels: coconut oil and olive oil.
Figure 3: Postprandial glycaemic and insulinaemic responses (AUCs for 180min) after consumption of test bread (Mean values with their standard errors for fifteen healthy young men | Lau. 2016)
As the authors point out in the discussion of the results of their study, their regression analysis "further confirmed that CI [=indicator of ALC formation] was a significant predictor of GR [glucose response], although it only accounted for 13·3 % of the observed variability" (Lau. 2016). Furthermore, the scientists highlight that ...
"[w]hen examined as IAUC, COC showed the greatest attenuation of GR [glucose response] in baked bread. A similar study by Clegg et al. (2012) showed that high-fat pancakes containing MCT had the slowest gastric emptying rate as compared with other fats/oils over a 4-h period. The low GR [glucose response] of COC in this study could be due to a combination of factors. These include delay in gastric emptying rates to MCT having a higher osmolarity (Clegg. 2012) and formation of ALC resulting in resistant starch (Kaur. 2000)" (Lau. 2016).
To assess the physiological significance of these observations, Lau et al. also investigated the surrogate measures of postprandial β-cell function (IGI30 and IGR) and the insulin response which did - in contrast to the glucose response (see Figure 3), not correlate with the ALC content of the breads. Instead, it appeared to be "partially due to rate of appearance of glucose as a result of carbohydrate digestibility" (Lau. 2016).
Will the additional butter on top of the potatoes reduce the insulin response? You can find the answer to this and the other questions in today's episode of "True or False?" | learn more!
So, what's the verdict? Well, adding ~25g of fat to bread increases its energy content significantly. Therefore, it is not clear how advantageous the improvements in glycaemia observed in the study at hand will actually be - after all, calories still count!

With that being said, the scientists' conclusion that "[t]he incorporation of fats during bread baking reduces GR, with the greatest attenuation seen in COC," is a significant result. One that can be partly explained by the reduction in carbohydrate digestibility via ALC formation, but not by any effects on the insulin response to the meal (if you fear insulin, adding fat is thus not going to cut it | learn more).

That the 'coconut advantage' is due to lauric acid and myristic acid in coconut oil is likely, but warrants further investigation; the same goes for the scientists' concluding remark that "[t]he use of simple dietary interventions (addition of functional lipids during cooking of carbohydrate-rich staple foods) may be an effective and practical strategy for improving glycaemic control, and may help in the prevention and management of [...T2DM] and CVD" (Lau. 2016) | Comment!.
References:
  • Clegg, Miriam E., et al. "Addition of different fats to a carbohydrate food: Impact on gastric emptying, glycaemic and satiety responses and comparison with in vitro digestion." Food Research International 48.1 (2012): 91-97.
  • Kaur, Kulwinder, and Narpinder Singh. "Amylose-lipid complex formation during cooking of rice flour." Food Chemistry 71.4 (2000): 511-517.
  • Lau, et al. "Effect of fat type in baked bread on amylose–lipid complex formation and glycaemic response." British Journal of Nutrition, Published online: 22 April 2016.

Minggu, 24 April 2016

Discontinuing the Set When You Slow Down on Squats May Boost Strength Gains + Preserve MHC-IIX Fiber Percentage

You want to get rid of those tiny weights and squat big time? Maybe you should watch your squatting velocity... and no, I am not talking about slowing down - rather about keeping your rep speed.
While the headline may suggest that this is yet another article about time under tension, the "speed" I refer to in the headline is only indirectly related to the TUT concept. Rather than that, speed, in this case, refers to the velocity with which you squat... or, to be more precise, the magnitude of repetition velocity loss allowed in each set (20% vs 40%) and its effects on structural and functional adaptations in response to resistance training (RT).

Previous studies have shown that the degree of neuromuscular fatigue induced by RT protocols can be monitored by assessing the repetition velocity loss within a set (Sanchez-Medina. 2011).
Different velocity loss schemes may also be used as part of classic periodization schemes.

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In the study at hand, the scientists did thus use a novel, velocity-based approach to resistance training programming, in which the fixed number of repetitions you have to perform with a given load is replaced by two hitherto largely ignored, closely related variables:
  • the repetition’s mean velocity (how far are you squatting down and getting back up), which is intrinsically related to relative loading magnitude, and
  • the velocity loss to be allowed, expressed as a percent loss in mean velocity from the fastest (usually first) repetition of each exercise set.
In practice this means that you (a) can only select weights with which you can perform the exercise with perfect form at the given speed and (b) you will have to drop the bar, as soon as the prescribed percent velocity loss limit is exceeded - a velocity limit that was set to either 20% or 40% in a recent study from the Pablo de Olavide University (Pareja-Blanco. 2016).
Table 1: Descriptive characteristics of the velocity-based squat training program performed by both experimental groups | Data are mean SD. Only one exercise (full squat) was used in training (Pareja-Blanco. 2016).
The scientists recruited twenty-four young and healthy men (age 22.7 1.9 years, height 1.76 0.06 m, body mass 75.8 7.0 kg)m who volunteered to participate in this study. Their initial 1RM strength for the full (deep) squat (SQ) exercise was 106.2 +/- 13.0 kg (1.41 0.19 normalized per kg of body mass). All subjects were physically active sports science students with a RT experience ranging from 1.5 to 4 years (1–3 sessions/week) and were accustomed to performing the squat exercise with correct technique. The subjects trained twice a week (48–72 h apart) during 8-week for a total of 16 sessions. A progressive RT program which comprised only the squat as the sole exercise was used (Table 1).
"The two groups trained at the same relative loading magnitude (per centage of one-repetition maximum, %1RM) in each session but differed in the maximum percent velocity loss reached in each exercise set (20% vs 40%). As soon as the corresponding target velocity loss limit was exceeded, the set was terminated. Sessions were performed in a research laboratory under the direct supervision of the investigators, at the same time of day ( 1 h) for each subject and under controlled environmental conditions (20 °C and 60% humidity). Subjects were required not to engage in any other type of strenuous physical activity, exercise training, or sports competition for the duration of the present investigation. Both VL20 and VL40 groups were assessed on two occasions: 48 h before (Pre) and 72 h after (Post) the 8-week training intervention. Training compliance was 100% of all sessions for the subjects that completed the intervention" (Pareja-Blanco. 2016).
Pre- and post-training assessments included: magnetic resonance imaging, vastus lateralis biopsies for muscle cross-sectional area (CSA) and fiber type analyses, one-repetition maximum strength and full load-velocity squat profile, countermovement jump (CMJ), and 20-m sprint running - the analysis yielded the following results:
  • The VL20 group trained at a significantly faster mean velocity than those from VL40 (0.69 +/- 0.02 vs 0.58 +/- 0.03 m/s, respectively; P < 0.001), but did sign. less reps [VL40 performed more repetitions (P < 0.001) than VL20 (310.5 +/- 42.0 vs 185.9 +/- 22.2)]. 
  • The mean fastest repetition during each session (that which indicates the relative magnitude of the load being lifted) did not differ between groups (0.75 +/- 0.03 vs 0.76 +/- 0.01 m/s, for VL40 and VL20, respectively) and initial repetition velocities matched the expected target velocities for every training session. 
  • The VL40 group reached muscle failure during 27.0 +/-  4.2 sets (56.3% of total training sets), the VL20 group did not reach failure at all. 
  • Total work was significantly greater for VL40 compared to VL20 (200.6 +/- 47.1 vs 127.5 +/- 15.2 kJ, P < 0.001).
Now based on the often-heard and actually scientifically backed assumption that increases in total volume and training to failure are both conducive to strength gains, we should expect that the VL40 group saw greater increases in muscle size and 1RM strength. This was yet not the case. 
Figure 1: Rel. changes in selected neuromuscular performance variables from pre- to post-training for each group;
p-values indicate the significance of time x group effects, meaning only the inter-group difference in
counter-movement jump performance is statistically significant (Pareja-Blanco. 2016).
Instead, (1) VL20 resulted in similar squat strength gains as VL40, (2) VL20 resulted in greater improvements in CMJ (9.5% vs 3.5%, P < 0.05), and (3) both groups saw identical increases in mean fiber CSA.
Figure 2: Changes in muscle volume for: (a) Whole quadriceps femoris; (b) rectus femoris (RF); (c) vastus medialis (VM); and (d) vastus lateralis plus vastus intermedius (VL+VI | Pareja-Blanco. 2016).
And the above occured in spite of the fact that the VL20 performed 40% fewer repetitions and never reached failure. Can't be? Well, you're right, there's more to the story:"Although both groups increased mean fiber CSA and whole quadriceps muscle volume, VL40 training elicited a greater hypertrophy of vastus lateralis and intermedius than VL20" (Pareja-Blanco. 2016). 
Figure 3: Changes in muscle cross-sectional areas and muscle fiber types percentages, from pre- to post-training for each group, using myofibrillaro adenosine triphosphatase histochemestry; p-values indicate the significance of time x group effects, meaning only the MHC-IIX fiber reduction was sign. different between groups (Pareja-Blanco. 2016).
On the other hand, the VL40 group saw a not exactly strength conducive reduction of myosin heavy chain IIX percentage in the muscle - a change that did not occur in the VL20 group - quite obviously an "endurance" adaptation, the benefit / harm of which would be sport-dependent.
Mo, We, Fr - Sequence of Hypertrophy, Power & Strength Will Up Your Gains on the Big Three (Squat, Bench, Deadlift) / Squat, bench press, deadlift - All major three benefit from the right order in your daily undulating periodization program (DUP) - This is how it works... | learn more
Bottom line: Since this is the first study to probe the effect of two isoinertial RT programs differing in the magnitude of velocity loss experienced during each exercise set on muscle structure and performance, I believe it would be preliminary to draw any conclusions about training in general, but it is unquestionably intriguing that this new way of programming RT regimen in scientific studies did not confirm the classic "higher volume + train to failure = increased gains"-conundrum. Instead, it would appear that using a significant drop in your rep velocity (instead of voluntary failure) as a guide will produce similar size and marginally superior strength gains... at least in trained subjects for the squat exercise.

The latter limitation already reveals: We will need more research to determine how the rep velocity influences the adpatational response to exercise in other subjects, other exercises, training frequencies, intensities, other time-frames and so on and so forth | Comment!
References:
  • Pareja‐Blanco, F., et al. "Effects of velocity loss during resistance training on athletic performance, strength gains and muscle adaptations." Scandinavian Journal of Medicine & Science in Sports (2016).
  • Sanchez-Medina, Luis, and Juan José González-Badillo. "Velocity loss as an indicator of neuromuscular fatigue during resistance training." Med Sci Sports Exerc 43.9 (2011): 1725-1734.

Sabtu, 23 April 2016

BFR, Detraining Mass & Strength | Multiple Sets Multiply 'Ur EE | 1- vs. 2-Arm Kettle Bell Swings Rock the Core & More

The # of hands you use to hold your KB while doing swings determines core muscle activity.
With the publication of the latest issue of the The Journal of Strength & Conditioning Research (May 2016 - Volume 30 - Issue 5 | read it), the time has come to do a training science update with data on the effects on blood flow restriction on strength and size gains during detraining, the energetic demands of single vs. multi-set training, the highly significant core muscle activity patterns with single- vs. two-arm kettlebell swings and a handful of auxilliary studies summarized in the bottom line... Sounds interesting? Well, then I don't want to keep you any longer. Let's see which insights said studies have to offer...
You can use BFR powered detraining in your periodization schemes.

30% More on the Big Three: Squat, DL, BP!

Mix Things Up to Make Extra-Gains

Linear vs. Undulating Periodizationt

12% Body Fat in 12 Weeks W/ Periodizatoin

Detraining + Periodization - How to?

Tapering 101 - Learn How It's Done!
  • Low intensity blood flow restriction training done during three times per week during 6 weeks of detraining helps maintain mass in in phys. active subjects (Kim. 2016).

    Compared to vigorous cycling at 60–70% of the subjects' individual heart rate reserve [HRR] without BFR, the low-intensity cycling protocol (30% HRR) with BFR (160–180 mm Hg) Kim et al. prescribed to their subjects, thirty-one healthy college-aged males (22.4 ± 3.0 years, range: 19–30 years), actually increased the leg lean mass of the subjects over time.
    Table 1: Strength and body composition data - *LI-BFR = low-intensity cycling with BFR; CON = control; BFLBM = bone-free lean body mass; ES = effect size; VI = vigorousintensity (Kim. 2016)
    The strength development in both groups was identical, though. This and the fact that cycling is not exactly what you should do to maintain strength and size (learn more about detraining) are yet things you have to keep in mind, before freaking out about how "awesome" BFR is.
  • Study unsurprisingly confirms the superior energy requirements of multiple- vs. single-set workouts - Difference is larger than 100%, in young men and women (Mookerjee. 2016).

    In their study, the researchers from the Universities of Pennsylvania and Cumberlands, as well as the College of New Jersey compare energy expenditure (EE) of single-set and multiple-set resistance exercise protocols using indirect calorimetry.
    Table 2: Loads (kg) used for each exercise presented by gender and combined data (Mookerjee. 2016).
    Twelve men and twelve women (age = 21.4 ± 1.3 years) performed a single-set (SS) and multiple-set (MS) resistance exercise protocol in random order. The subjects performed two protocols at 70% of their 1-repetition maximum. The protocols consisted of 5 upper-body exercises of either 1 or 3 sets per exercise performed in random order. Metabolic and cardiorespiratory data were recorded over the entire exercise session and during 5 minutes of recovery by a portable metabolic measurement system.
    Figure 1: Gross and net (left), as well as relative (per lbm) EE in kcal during SS (single set) and MS (multiple set) training in male and female study participants (Mookerjee. 2016).
    As you can see in Figure 1, the gross (167.9 ± 58.7 kcal) and net (88.3 ± 41.6 kcal) EE for the MS protocol were significantly greater (p < 0.001) than gross (71.3 ± 26.5 kcal) and net (36.3 ± 18.7 kcal) EE of the SS protocol. Conversely, there was no significant difference in the rate of EE between both protocols. Heart rate, respiratory rate, relative V[Combining Dot Above]O2, respiratory exchange ratio, and minute ventilation values were significantly higher during the MS than the SS protocol.

    As it was to be expected, a significant gender difference (p < 0.001) in absolute and relative EE was observed for both protocols where values in men were higher than women. 
  • Doing kettle bell swings with one vs. two arms induces a greater neuromuscular activity for the contralateral side of the upper erector spinae and ipsilateral side of the rectus abdominis, and lower activation of the opposite side of the respective muscles (Anderson. 2016).

    The aim of the study of this study from Norway was to compare the electromyographic activity of rectus abdominis, oblique external, and lower and upper erector spinae at both sides of the truncus in 1-armed and 2-armed kettlebell swing. To this ends, the researchers had sixteen healthy men perform 10 repetitions of both exercises using a 16-kg kettlebell in randomized order.
    Figure 2: Comparison of the EMG activity of the core muscles 1- vs. 2-armed kettle bell swings in sixteen healthy men (age, 25 ± 6 years; body mass, 80 ± 8 kg; stature, 180 ± 7 cm) with 7 ± 7 years of resistance training experience (Anderson. 2016)
    As the data in Figure 2 reveals, For the upper erector spinae, the activation of the contralateral side during 1-armed swing was 24% greater than that of the ipsilateral side during 1-armed swing (p < 0.001) and 11% greater during 2-armed swing (p = 0.026). Furthermore, the activation in 2-armed swing was 12–16% greater than for the ipsilateral side in 1-armed swing (p < 0.001). For rectus abdominis, however, 42% lower activation of the contralateral side was observed during 1-armed swing compared with ipsilateral sides during 2-armed swing (p = 0.038) and 48% compared with the ipsilateral side during 1-armed swing (p = 0.044). Comparing the different phases of the swing, most differences in the upper erector spinae were found in the lower parts of the movement, whereas for the rectus abdominis, the differences were found during the hip extension. In contrast, similar muscle activity in the lower erector spinae and external oblique between the different conditions was observed (p = 0.055–0.969). In conclusion, performing the kettlebell swing with 1 arm resulted in greater neuromuscular activity for the contralateral side of the upper erector spinae and ipsilateral side of the rectus abdominis, and lower activation of the opposite side of the respective muscles.
Normalized electromyography (EMG) amplitude values (mean 6 SD) for the straight and hexagonal barbells, collapsed across 65 and 85% 1 repetition maximum loads (Camara. 2016) |  ++ significant advantage of regular bar; + significant advantage of hexagnoal bar.
What else have we got? Well, there are Trexel's previously discussed popular creatine vs. caffeine study discussed in July 2015 (read more) and Ohya's 400- and 800-m track running study showing that even trained females' performance suffers from inspiratory muscle fatigue after short-duration running exercise, suggesting that "[c]oaches could consider prescribing inspiratory muscle training or warm-up in an effort to reduce the inevitable IMF associated with maximal effort running" (Ohya. 2016).

Furthermore, Camara's previously (only in the Facebook news) discussed study showing differences in the muscle activity pattens (data see Figure on the right) and significantly greater peak force, peak power, and peak velocity for deadlifts with hexoganal vs. regular bars, and, last but not least has now been officially published.

Last, but not least, Beyer's study showing that 4 weeks of unilateral strength training results in "an increase in strength and size of the trained musculature, and cross education of strength in the untrained musculature, which may occur without detectable changes in muscle size, activation, or the acute hormonal response" (Beyer. 2016) as well as two studies I will discuss in detail, next week, should not be forgotten either | Comment on Facebook!.
References:
  • Andersen, V, Fimland, MS, Gunnarskog, A, JungÃ¥rd, G-A, SlÃ¥ttland, R-A, Vraalsen, ØF, and Saeterbakken, AH. Core muscle activation in one-armed and two-armed kettlebell swing. J Strength Cond Res 30(5): 1196–1204, 2016
  • Camara, KD, Coburn, JW, Dunnick, DD, Brown, LE, Galpin, AJ, and Costa, PB. An examination of muscle activation and power characteristics while performing the deadlift exercise with straight and hexagonal barbells. J Strength Cond Res 30(5): 1183–1188, 2016
  • Kim, D, Singh, H, Loenneke, JP, Thiebaud, RS, Fahs, CA, Rossow, LM, Young, K, Seo, D-i, Bemben, DA, and Bemben, MG. Comparative effects of vigorous-intensity and low-intensity blood flow restricted cycle training and detraining on muscle mass, strength, and aerobic capacity. J Strength Cond Res 30(5): 1453–1461, 2016
  • Mookerjee, S, Welikonich, MJ, and Ratamess, NA. Comparison of energy expenditure during single-set vs. multiple-set resistance exercise. J Strength Cond Res 30(5): 1447–1452, 2016
  • Ohya, T, Yamanaka, R, Hagiwara, M, Oriishi, M, and Suzuki, Y. The 400- and 800-m track running induces inspiratory muscle fatigue in trained female middle-distance runners. J Strength Cond Res 30(5): 1433–1437, 2016.
  • Trexler, ET, Smith-Ryan, AE, Roelofs, EJ, Hirsch, KR, Persky, AM, and Mock, MG. Effects of coffee and caffeine anhydrous intake during creatine loading. J Strength Cond Res 30(5): 1438–1446, 2016