Each +30 Min/d of Physical Activity Reduce HbA1c by 11%, Protein + CHO Maintain Bone Mass, Overlooked Benefits of BFR, New Marker of Overtraining - Jan '17 Science Update

  This is what the Jan '17 Science Update has to offer? -11% HbA1c reduction per 30 minutes activity, new benefits of blood flow restricted tr., the bone protective effect of immediate post-workout whey plus carb ingestion, and a new overtraining gauge...

It's almost, February... almost and that's why today's SuppVersity article still qualifies as a January '17 research update. One that is based on the latest (ahead of print) papers from the peer-reviewed journal "Medicine & Science in Sports & Exercise" - papers about the large impact of short bouts of moderate-to-vigorous physical activity (MVPA) on the messed up glucose management of people with an increased T2DM risk, the bone-preserving effects of a mix of whey and dextrose and how this effect depends on timing, the belated and thus overlooked beneficial effects of blood flow restriction on muscular rapid force development and, last but not least, a potential new marker of overreaching and -training that could also explain the dichotomous role of IL-6 in the adaptive and maladaptive response to exercise.

Learn more about blood flow restriction at the SuppVersity

BFR for VO2 & Strength Gains

Using BFR in Periodization

BFR Precondi-tioning = Useless

Benefits of Cuffs After sets?!

No Extra-Gains W/ BFR vs. HIT

Hormonal Re-sponse to BFR

• Scientists find new marker of overreaching and potentially -training: You know that exercise will increase the levels of the allegedly "bad" cytokine IL-6. Now, as a SuppVersity reader, you will yet also know that this "cytokine" is, in fact, a "myokine" if it is released in response to muscle contractions and that it appears to figure in the hormetic response to exercise stress... or, in other words, without it, you're not going to get the adaptational response in form of strength and size gains you're training for. With that being said, studies also show that significantly elevated levels of IL-6 can also occur with overtraining and are - in this situation - a sign of dysfunctional adaptation.
  
  Recent research does now suggest that the "dichotomous nature of IL-6 signalling appears to be determined by the respective concentration of its receptors (both membrane-bound (IL-6R) and soluble (sIL-6R) forms)" (Cullen. 2017) - measuring these concentrations could thus provide important information about whether the circulating IL-6 is going to trigger a hormetic response or not. Accordingly, Cullen et al. conducted a study that investigated the response of sIL-6R to long-term training, and the relationship between sIL-6R, self-reported measures of wellbeing, and upper respiratory illness symptoms (URS) in highly-trained endurance athletes.
  

  

  Figure 1: Unlike cortisol, which has a long history as a suspected, but rarely useful overtraining gauge, sIL-6R doesn't have a circadian rhythm (see explanation in green box). This doesn't mean it's an accurate marker of overtraining, but it does mean that it is less complicated and more convenient to use, because with overtraining the circadian rhythm can be so messed up that simply measuring at the same time won't suffice to get comparable and thus useful results to gauge your training status.

  Their results are quite conclusive: Firstly, they confirmed that sIL-6R is responsive to prolonged periods of exercise training. And second- and more importantly, the subjects' sIL-6R levels varied according to the individual training volume and could be linked to common symptoms of overreaching such as high levels of stress, and/or depressed mood.
  
  This is obviously not enough to use sIL-6R as an overtraining gauge. With future studies that determine the level of sIL-6R in overreaching and overtraining athletes, it may thus be possible to distinguish between these states (and regular training) and to use this information to optimize athletes and gymrats workout routines. 
• Rapid Force Capacity (RFC) increases sign. with blood flow restriction, but study shows: Adaptation takes time: This observation Nielsen, et al. (2017) made in their recent study is an important one, because it implies that previous studies on the effects of blood flow restriction + low-intensity training may simply have missed the beneficial effects when they measured (just as Nielsen, et al. did it, too), the adaptational response only 5 days after having subjects participate in a series of standardized workouts.
  
  In the study at hand, this series constituted of twenty-three training sessions which were performed within 19 days. In all 10 male subjects (22.8+/-2.3 years) who performed four sets of knee extensor exercise (20%1RM) to concentric failure during concurrent BFR of the thigh (100mmHg), and the eight work-matched controls (21.9+/-3.0 years) who trained without BFR (CON), the scientists tested the maximal slow and fast knee joint velocity muscle strength and rapid force capacity (e.g. RTD) as well as evoked twitch contractile parameters before and after the study.
  

  

  Figure 2: Changes in rate of force development (left) and mean muscle fibre area (right | Nielsen. 2017).

  Now, that's nothing new. What was new, however, is that they tested before (Pre) and 5 and 12 days after training (Post5, Post12). In conjunction with the data from the biopsies, Nielsen et al. were thus able to detect the improved rate of torque development for the first time. The sign. difference in muscle fiber area (Figure 2, right), on the other hand, is - interesting as it may be - no news: after all, we're comparing light load with BFR to light load w/out BFR and not, as many other studies did, light load BFR to regular high load training, where time and again the regular training group saw the greater muscle increases.
• Each extra 30 minutes of daily moderate to vigorous physical activity improve HbA1c of subjects at increased T2DM risk by 11%: MVPA aka "moderate to vigorous physical activity" is the buzzword of the fitness tracker generation. Now, a three-year study confirms what the medals your fitness tracker software will award to you already suggested: each minute spend moving at moderate to vigorous intensity is an investment into your health and well-being.
  
  

  

  How Accurate Are Activity Trackers? EE Data From Omron, Fitbit, Jawbone & Other Devices Reveals 10% Error & More | read the full SV article

  The above is the result of a recent study that correlated longitudinal (three-year follow-up) activity tracker data with changes of the long-term glucose marker HbA1c in a sample of 489 men and women at high risk of developing type II diabetes, participants (mean age 64.2 +/- 7.3 years, BMI 31.7 +/- 5.1, 63.4% male). And it's a result based on which the authors, Mathew McCarthy, and colleagues, rightly conclude that "[i]ncreases in MVPA and body weight were associated with a reduction and increase in HbA1c respectively, particularly in those with dysglycemia" (McCarthy. 2017).
• Immediate Protein + CHO post-workout nutrition protect your bone from the bone resorption in the hours after exhaustive running: Next to its important result, there are two things which make a recent study by Rebecca Townsend et al. particularly interesting. Firstly: The subjects were young, healthy men, not post-menopausal women as in so many other bone health studies; and second- and not less importantly, the study tested both the efficacy of a mix of 1.5g/kg dextrose + 0.5g/kg whey as a means to reduce bone resorption (=calcium leeching) markers and the effects of timing.
  

  

  Figure 3: Overview of the study design, note that active treatment or PLA were administered at three different time points with two servings of placebo ensuring that the subjects could not differentiate between the immediate supplementation, the 2h-post and 4h-post supplementation trial (Townsend. 2017).

  And guess what. The study, in the course of which the dextrose + whey drinks were administered either before or after a placebo drink immediately or 2h after the run (see Figure 3) did not just confirm that the nutrient mix can ameliorate and shorten the exercise-induced (75% VO2Max run to exhaustion) increase in the bone resorption markers β-CTX and P1NP, it also found that this effect is time-dependent with the administration of the dextrose + whey mix right after the workout having more beneficial effects than taking it 2h post. With the immediate consumption reducing the levels below pre-exercise levels (-22% to -61%) within 1h, while it remained elevated with the placebo drink and/or in the DF group in which the supplement was consumed 2h after the workout. Now all that could well be a mere time-shift in the bone anabolic response. The scientists' observation that "[t]he overall β-CTX response was significantly lower in the IF trial than the DF trial (P=0.019, d=0.37) and the PLA trial (P≤0.001, d=0.84)" (Townsend. 2017) does however clearly suggest a definite benefit of immediate (IF) vs. postponed (DF and PLA) nutrient consumption after exhaustive workouts.
  
  In this context, however, it is important to realize that that, eventually, i.e. 3-4h after the run, the level of β-CTX decreased to similar below pre-test levels in all groups. Practically speaking this means that the net effect of a single session of exhaustive exercise on the young men's bone was almost certainly positive, irrespective of whether and when they ingested the supplement.

What's the take away of the studies in this Science Update: For me personally, the most important lesson comes from the MVPA study by McCarthy et al. (2017). A mere 30 minutes of "exercise" (even fast walking would qualify) is after all an easily manageable workload of that will contribute to statistically and, more importantly, clinically significant improvements in blood glucose management.

Drop the weights, grab the shake! Timing matters for advanced trainees.

Sort of surprising was the time-dependence of the beneficial effects of a dextrose + whey mix on bone resorption after exhaustive running in young male subjects. As I hinted at in the discussion of the study, however, we got to be careful not to mistake a timeshift in the response for an actual improvement.

Imho, future (best longitudinal studies) should investigate the net effect on bone mass to avoid a similar confusion as we've had them for protein supplements of which the majority of studies refutes that their ingestion in the immediate vicinity of the workout would improve your gains.

Last but not least, there's Nielsen's BFR study, which doesn't just prove another hitherto overlooked benefit of blood flow restricted low-intensity training, but also constitutes a lesson in study design, which reminds us that the timing of a retest will often determine if you find an effect or not. Apropos timing, while the latter may matter less for sIL-6R data than it does for cortisol, there's still a lot of research necessary to confirm the validity of this new marker of overreaching and -training and develop reliable tests for athletes and gymrats | Comment on Facebook!

References:

• Cullen, Tom; Thomas, Andrew W.; Webb, Richard; Phillips, Thom; Hughes, Michael G. "sIL-6R Is Related to Weekly Training Mileage and Psychological Well-being in Athletes." Medicine & Science in Sports & Exercise: Post Acceptance: January 24, 2017.
• McCarthy, Matthew; Edwardson, Charlotte L; Davies, Melanie J; Henson, Joseph; Gray, Laura; Khunti, Kamlesh; Yates, Thomas. "Change in Sedentary Time, Physical Activity, Bodyweight, and Hba1c in High-Risk Adults." Medicine & Science in Sports & Exercise: Post Acceptance: January 24, 2017.
• Nielsen, Jakob Lindberg; Frandsen, Ulrik; Prokhorova, Tatyana; Bech, Rune Dueholm; Nygaard, Tobias; Suetta, Charlotte; Aagaard, Per. "Delayed Effect of Blood-Flow-Restricted Resistance Training on Rapid Force Capacity." Medicine & Science in Sports & Exercise: Post Acceptance: January 23, 2017. 
• Townsend, Rebecca; Elliott-Sale, Kirsty J.; Currell, Kevin; Tang, Jonathan; Fraser, William D.; Sale, Craig. "The Effect of Postexercise Carbohydrate and Protein Ingestion on Bone Metabolism." Medicine & Science in Sports & Exercise: Post Acceptance: January 24, 2017.

Low Grade Metabolic Acidosis May Eat Away Your Bones and Blow Up Your Belly Via Empowering Glucocorticoids!

The way we eat and live is not just obesogenic it is also acidogenic... or is the former just a consequence of the latter? 

I've written about the nasty effects of low grade metabolic acidosis which include calcium loss and brittle bones, nitrogen / protein loss and decreased protein synthesis, impaired growth hormone and IGF-1 production and more in a 2013 SuppVersity Science Round-Up (read it).

For you, as a SuppVersity veteran who's read this and related articles, it should thus not be surprising that scientists from the German Aerospace Center in Cologne were now able to establish a new, mechanistic link between the "long-term ingestion of habitually acidifying western diets may constitute an independent risk factor for bone degradation and cardiometabolic diseases" (Buehlmeier. 2015).

As Judith Buehlmeier and her colleagues point out, we have long been aware of the ill effects of low-grade metabolic acidosis (LGMA), as induced by high dietary acid load or sodium chloride (NaCl) intake and a lack of alkaline foods and nutrients in the average Western diet. What has hitherto not been fully elucidated is the underlying mechanisms, which is not as simple as the dissolving tooth in a glass of coke would suggest.

You can learn more about bicarbonate and pH-buffers at the SuppVersity

The Hazards of Acidosis

Build Bigger Legs W/ Bicarbonate

HIIT it Hard W/ NaCHO3

Creatine + BA = Perfect Match

Bicarb Buffers Creatine

Alkalosis Boosts Muscle Activity

In their latest study, the researchers from the German Aerospace Center in Cologne and their colleagues from the Universities of Bonn and Heidelberg do now present the first convincing evidence that the previously cited catabolic / anti-anabolic effects of chronic low-grade acidosis (LGMA) are triggered by interactions of the acid–base balance with the metabolism of glucocorticoids (GC). In said, study, the researchers "aimed to investigate GC activity/metabolism under alkaline supplementation and NaCl-induced LGMA" in eight young, healthy, normal-weight men who participated in two crossover designed interventional studies.

Figure 1: Correcting a diet-induced low grade metabolic acidosis with K-bicarbonate reduces the nitrogen loss of 750mg - 1000mg per day (per 60kg BW) in post- menopausal women in a prev. study (Frassetto. 1997)

• In Study A, two 10-day high NaCl diet (32 g/d) periods were conducted, one supplemented with 90 mmol KHCO3/day.
   
• In Study B, participants received a high and a low NaCl diet (31 vs. 3 g/day), each for 14 days. During low NaCl, the diet was moderately acidified by replacement of a bicarbonate-rich mineral water (consumed during high NaCl) with a non-alkalizing drinking water. 

In repeatedly collected 24-h urine samples, potentially bioactive GCs (urinary-free cortisol / free cortisone), as well as tetrahydrocortisol (THF), 5a-THF, and tetrahydrocortisone (THE), were analyzed.

Even Low Grade Acidosis Will Increase Your Diabetes Risk | learn more!

Beware! It does not take much to mess you up! A quantitative analysis of the data from the study at hand shows that even increases of dietary acid loads in the magnitude of only 30 mEq/d, which drive the renal net acid excretion into a range that is commonly seen in people on the standard Western diet (60–70 mEq/d), suffice to affect glucocorticoid activity in ways that may ruin your bone, heart and muscle health. In that, the main offenders are grains, not meats. Grains contribute an estimated 38% to the net acid load of the avg. Westerner (Sebastian. 2002).

A brief glimpse at the glucocorticoid levels in the urine of the subjects (see Figure 2) shows that with supplementation of 90 mmol KHCO3, the marker of total adrenal GC secretion dropped (p = 0.047) and potentially bioactive-free GCs were reduced (p = 0.003).

Figure 2: aily adrenal cortisol secretion as indexed by the sum of excretion rates of the 3 major urinary glucocorticoid (GC) metabolites tetrahydrocortisol, 5a-tetrahydrocortisol, and tetrahydrocortisone (THF + aTHF + THE) as well as excretions of potentially bioactive-free GCs (UFF + UFE | Buehlmeier. 2015)

This is particularly interesting if we also take into account that in Study B, the GC secretion and potentially bioactivefree GCs did not exhibit the expected fall with NaCl-reduction as net acid excretion was raised by 30 mEq/d. In conjunction study A + B do thus underline the important role of alkalizing agents like bicarbonate or potassium - irrespective of the total intake of NaCl, of which the study at hand confirms that it is part of the problem. Its ill effects, however, appear to be mediated mainly, if not exclusively, via the acidifying effects of chloride.

Bottom line: As the authors point out, their study is the first to provide convincing evidence that the ill effects of chronic low-grade metabolic acidosis are mediated via enhanced glucocorticoid activity and secretion. In that, the pro-acidic effects of NaCl, as well as the lack of alkalizing foods and nutrients in the Western diet are the main motors of dietary induced glucocorticoid elevations.

Inactivity amplifies the ill effect of glucocorticoids on muscle loss by up to 213% (Ferrando. 1999).

These elevations are - in spite of being still in the physiological range - significant enough to compromise bone quality (Bedford. 2010; Shi. 2015), cardiometabolic health & diabetes (Prodam. 2013; Qi, 2007), and protein turnover (Frassetto. 1997 | see Figure 1; Buehlmeier. 2012), and appear to be particularly unfavorable under conditions of physical inactivity (Ferrando. 1999 | see Figure on the right). Reason enough for the authors to conclude that "[a]ccordingly, higher dietary acid loads may, in the long run, constitute an independent GC-driven musculoskeletal and cardiometabolic risk factor related with western dietary habits" (Buehlmeier. 2015) | Comment!

References:

• Bedford, Jennifer L., and Susan I. Barr. "The relationship between 24-h urinary cortisol and bone in healthy young women." International journal of behavioral medicine 17.3 (2010): 207-215.
• Buehlmeier, Judith, et al. "Alkaline salts to counteract bone resorption and protein wasting induced by high salt intake: results of a randomized controlled trial." The Journal of Clinical Endocrinology & Metabolism 97.12 (2012): 4789-4797.
• Ferrando, Arny A., et al. "Inactivity Amplifies the Catabolic Response of Skeletal Muscle to Cortisol 1." The Journal Of Clinical Endocrinology & Metabolism 84.10 (1999): 3515-3521.
• Frassetto, L., R. Curtis Morris Jr, and A. Sebastian. "Potassium bicarbonate reduces urinary nitrogen excretion in postmenopausal women." The Journal of Clinical Endocrinology & Metabolism 82.1 (1997): 254-259.
• Qi, Dake, and Brian Rodrigues. "Glucocorticoids produce whole body insulin resistance with changes in cardiac metabolism." American Journal of Physiology-Endocrinology and Metabolism 292.3 (2007): E654-E667.
• Prodam, Flavia, et al. "High-end normal adrenocorticotropic hormone and cortisol levels are associated with specific cardiovascular risk factors in pediatric obesity: a cross-sectional study." BMC medicine 11.1 (2013): 44.
• Sebastian, Anthony, et al. "Estimation of the net acid load of the diet of ancestral preagricultural Homo sapiens and their hominid ancestors." The American journal of clinical nutrition 76.6 (2002): 1308-1316.
• Shi, Lijie, et al. "Higher glucocorticoid secretion in the physiological range is associated with lower bone strength at the proximal radius in healthy children: importance of protein intake adjustment." Journal of Bone and Mineral Research 30.2 (2015): 240-248.

Nutrition & Age-Related Muscle Loss - Overview of Some Recent Studies: It Does not Take More Than Well-Timed ~20g of Milk Protein to Turn Muscle Loss into Gain + More

Ladies and gents, if you want to keep up with the youngsters and be able to play with your grand and grand-grand children you better put an emphasis on more than adequate protein intakes.

Initially I wanted to talk about only one of the studies that were presented at the latest meeting of the Nutrition Society, but in view of the facts that (1) we are all going to be old one day, (2) we all have parents and grand parents at risk of muscle loss and sarcopenia and (3) we all are interested in some good research, I thought it may be a good idea to summarize the most important findings of three additional relevant presentations.

Ah, before I get started: I would like to emphasize that the corresponding full papers have not been published, yet. I do thus apologize in advance that I won't be able to answer detail questions about the methods, side findings and allegedly interested, but hitherto unknown stuff like that.

Read more short news on various topics here at the SuppVersity

Exercise Research Uptake Nov '14 1/2

Exercise Research Uptake Nov '14 2/2

Weight Loss Supplements Exposed

Exercise Supplementation Quickie

Exercise Research Uptake Jan 12, 2015

Read the Latest Ex. Science Update

• It does not take more than ~20g of milk protein to turn muscle loss into gains (!) - It does sound almost too easy to believe, but researches from the University of Limerick were able to show that adding 0.33g/kg body weight milk protein may be all it takes not just to conserve, but actually to build lean muscle mass in people aged 50-70 year old.
  
  In their study, Norton et al. (2015) observed a highly significant increase in lean tissue mass of 1% in 24 weeks when the subjects who consumed a protein sufficient diet with 1.2g protein/kg body weight (that's 50% higher than the FDA minimum of 0.8g/kg) added only 0.3g/kg milk protein to their diets. The protein came from two shakes that were - and this may be important - consumed with the lowest protein meals of the day.

  

  Figure 2: Change sin lean tissue mass (relative and absolute) in response to 24-weeks of supplementation with two servings of 0.15g/kg body weight milk protein (total 0.3g/kg) or placebo in 50-70 year olds (Norton. 2015).

  So, assuming your grandma eats a high protein breakfast, has no appetite at lunch and consumes only a few slices of bread at dinner, she'd take the protein shakes with lunch and dinner. Depending on cultural and personal habits, the distribution is yet probably rather breakfast + launch (US) or dinner (Europe).

Don't be a fool! Nutrition is an important factor that will help you keep your muscle functional, but without proper "exercise" in the form of adequate physical activity and some form of "strength training" (body weight squats and push ups if you have no equipment) you will not be able maintain optimal muscle function, no matter how much protein you consume.

• Which reminds me: It would have been very interesting if the scientists had had one group of subjects consume all the milk protein with their larges meal of the day. If we believe in the "protein timind does not matter" mantra that has recently become popular (cf. Schoenfeld. 2013), it should not matter. Somehow I do believe, however that it would.
• DHA as performance booster for your grandma - In another recent study Dyall et al. observed that short-term supplementation with an enriched DHA supplement was associated with significant increases in blood DHA content and there were significant positive relationships between increased DHA status and improved fast walking speed and vertical jump height.
  
  

  

  Meta-Analysis Says: Fish Oil Does Not Help You Lean Out! Plus: Why you Should Still Eat Fish | more

  What is particularly interesting is that only potentially relevant inter-group difference the scientists testes was the DHA level which was significantly increase in response to the ingestion of the supplement that contained 1 g DHA, 160 mg EPA, 240 mg gingko biloba, 60 mg phosphatidylserirte, 20 mg d-alpha tocopherol, 1 mg folic acid and 20 pg vitamin B12 per day for 6 months. No other significant differences were found. A fact that suggests that "the effects were mediated via changes in DHA, rather than the other components in the treatment" (Dyall. 2015).

Can drinking protein shakes outperform dietary protein when it comes to protecting aged muscle from diet induced catabolism? Find out in this previous SuppVersity article @ March 2015 | read more

On short notice: Next to these findings, scientists also found that the majority of Britons still gets the lion's share of their dietary protein from animal products, with the average contribution of animal protein to the diets of men and women being 10.1% and 10.8% of the total energy intake (vs. 4.7% from plant protein | Bain. 2015). Since bone loss usually goes hand in hand with muscle loss, it may also be worth mentioning that one's susceptibility to seasonal changes in 25OHD levels are associated with increased bone resorption, i.e. the "deconstruction" of bone material (). That's an interesting observation researchers from the University of Sheffield have made - one that provides another good argument to (a) test your 25OHD levels regularly and to supplement if necessary (specifically during fall and winter) | Comment on Facebook!

References:

• Bain, LKM., et al. "Contributions to dietary protein intake in a British adult population". Proceedings of the Nutrition Society, 74, E179 (2015): doi:10.1017/S0029665115001974. 
• Darling, AL. "Increased bone resorption is associated with greater seasonal fluctuation or ‘cycling’ of 25-hydroxyvitamin D". Proceedings of the Nutrition Society, 74, E177 (2015): doi:10.1017/S0029665115001950. 
• Dyall,SC. et a. "Blood levels of the omega-3 fatty acid docosahexaenoic acid are associated with gait and lower limb power in older females". Proceedings of the Nutrition Society, 74, E168 (2015): doi:10.1017/S002966511500186X. 
• Norton, C,  et al. "Effect of 6 month supplemental milk protein intake on lean tissue mass in healthy adults aged 50 to 70 years". Proceedings of the Nutrition Society, 74, E181 (2015): doi:10.1017/S0029665115001998. 
• Schoenfeld, Brad Jon, Alan Albert Aragon, and James W. Krieger. "The effect of protein timing on muscle strength and hypertrophy: a meta-analysis." J Int Soc Sports Nutr 10.1 (2013): 53.