HMB Supplementation Also Works in Trained Subjects

While the positive effect of HMB on body composition and strength in untrained subjects is not controversial, the case doesn’t seem so for trained subjects but not for lack of positive data! 

Written by
Sérgio Fontinhas, CISSN

Key points: 

1. Studies lasting 6 weeks or less are too short to show positive results from HMB in trained subjects. 

2. Studies lasting more than 6 weeks can show positive results. 

3.Positive results also depend of training intensity, volume and supervision.

Strength Training, Bone Mineral Density and Growth in Adolescents

Does strength training impair growth in adolescents? If you think so you are falling into an old myth.

It has been known for decades that junior competitive weightlifters have an increased bone mineral density (BMC) well above the age-matched controls' mean (1). The effect of this type exercise appears to overcome any race or age-related BMC differences (1).

A Look Into Anabolic Steroid Use In Bodybuilding, Physique and Wellness Competitors

A new study looked into the practices of IFBB competitors. Six (four male and two female) bodybuilders (IFBB) and their coaches were directly interviewed for this study(1).


2 male Bodybuilders in the same category.
2 Men’s Physique competitors belonging to the same category.
2 women competing in different Wellness categories.

BCAAs and Insulin Resistance in Vegans

BCAA supplementation may not be suitable to vegans. These are some main points from a recent  preliminary study comparing vegans to omnivores supplementing with 15 g (women) or 20 g (men) of BCAA daily for 3 months:

New Protein Requirements for Bodybuilders

A new study sought to assess protein requirements at the whole-body level using the IAAO technique in trained subjects.


The RDA for protein is established at 0.8g/kg as the minimum protein intake to offset protein deficiency (net nitrogen losses) for 97.5% of the healthy population above 19 years (1). Believe it or not, the RDA was even deemed appropriate for healthy adults undertaking resistance or endurance exercise (2).

The RDA represents the estimated average requirement plus 2 standard deviations (3), determined from selected nitrogen-balance studies of which very few were performed in older individuals (4,5).

Nitrogen balance studies suffer from several methodologic concerns (6-10). In addition to the impractical need for repeated 7- to 10-d adaptation periods necessary to produce accurate NB data for each of the several protein intakes needed to determine the requirement (6), the use of a linear regression line with a greater residual error for analyzing nonlinear data is not a good fit for either NB or oxidation data (6,8,11).

There is also an over- or underestimation of nitrogen intake and excretion, respectively (6,12). Furthermore, NB may be achievable at low protein intakes for the brief study durations often used because of more efficient amino acid (AA) utilization, reduced turnover rates, and/or accommodation (6,13,14,15).

Better methods such as the indicator amino acid oxidation (IAAO) technique show that the RDA underestimated protein needs by 30-50% (16,17,18). The IAAO technique identifies the plateau in AA oxidation that corresponds to the maximum rate of whole-body protein synthesis.

When dietary protein is inadequate the oxidation of all AAs, including the indicator AA, will be substantial (6). With increasing dietary protein oxidation of the indicator AA will decrease because more AAs are being incorporated into body protein, and once the dietary requirement is met there is no further change in the oxidation of the indicator AA and the resulting ‘‘breakpoint’’ is thought to be the requirement (6,10).

Isotope tracer methodology is considered to be a far more accurate technique, and the IAAO technique was considered an acceptable method to assess protein requirements back in 2005 (6,19).

A protein intake of 0.93-1.2 g/kg/day, exceeding the current requirement by as much as 50%, was unveiled in men using the using the indicator amino acid oxidation technique (18). The results were comparable with those estimated by the application of a biphase linear regression model to the data from nitrogen balance studies (0.91 and 1.0 g/kg/d) (18). 

Nevertheless, the few available NB studies on bodybuilders are quite variable, and even very positive NB (3.8–20 g/d) with protein intakes of 1.8–2.7 g/kg/d observed in men engaged in a rigorous strength-training (ST) program do not result in the expected fat-free mass (FFM) accrual (3,6,19,20). For example, a positive NB (12–20 g N/d) at a protein intake of 2.8g/kg should produce 300–500 g lean mass gain/d, however this was not observed (20).

Stable isotope identified 4 different states of protein metabolism studies (6,14,15,21,22):
1) ‘‘protein deficiency,’’ defined as the maximal reduction in protein synthesis to all but the essential organs;
2) ‘‘accommodation,’’ in which balance is achieved via a decrease in physiologic relevant processes;
3) ‘‘adaptation,’’ in which optimal growth, interorgan AA exchange, and immune function are present; and
4) ‘‘excess,’’ which is characterized by AA oxidization for energy and nitrogen excretion via urea, resulting in no further stimulation of protein synthesis (15).

Regardless of age, when protein intakes near the current RDA are combined with Strength training, accommodation results through increased nitrogen utilization efficiency and lower whole-body protein synthesis rates rather than adaptation (6,19,21,23).

Current dietary protein recommendation for bodybuilders varies widely, from the RDA of 0.85g/kg/d (16) to as much as 2.0 g/kg/d (24).

During exercise there is an increase in aminoacid oxidation (1-5% of the total energetic cost of exercise), increased catabolism and increased muscle protein synthesis (25,26,27). Under-recovery is also another concern (25,28).

Protein requirements for bodybuilders in nontraining days

A new study sought to assess protein requirements at the whole-body level using the IAAO technique, in 8 individuals who had undergone regular bodybuilding training for more than 3 years (6). Subjects had a mean 84kg of body mass, 72.4 kg of LBM, and a fat free mass index of 24.

The Exercise “Spot Reduction” Myth

The “spot reduction” hypothesis states that exercise concentrated on a specific area will result in preferential reduction of the fat deposits in that specific area. For example, abdominal exercises are often promoted as an effective means to reduce abdominal fat and trim the waistline.

However results in scientific literature are mixed, especially old studies.  Spot reduction is generally not considered valid without creating a consistent energy deficit, and even in a caloric deficit it is no guarantee you will burn fat at the exercised region.

In 1956 "spot" reducing was deemed possible (1) but it was only in 1960 that this question was addressed scientifically.

The Epidemiology and Physiology of Sedentary Behavior

Physical inactivity is estimated to account for 6% of global deaths (1), and is associated with risk of Metabolic Syndrome and cancer (2,3,4).

Approximately 100,000 new cases of breast and colon cancer each year are linked to sedentary lifestyles (5). Another study found that taking frequent breaks from sitting is associated with smaller waist circumference and lower levels of C-reactive proteins, both biomarkers associated with elevated risk of some cancers for post-menopausal women (6).

The National Health and Nutrition Examination Survey (7) analyzed data of 4,757 participants and found that even short periods of light activity (standing up and walking for at least a minute) – reduced biomarkers such as large waist circumference, elevated triglyceride levels and increased insulin resistance.

Physiology of Dehydration and Overhydration

When the body is in a state of dehydration, many substrates and neurotransmitters are influenced by circulating vasopressin (antidiuretic hormone) and angiotensin II (1,2).

Dehydration can increase levels of cortisol (3). Interestingly, even a decrease in cell volume caused by hypohydration promotes insulin resistance (4,5,6).
Conditions dehydrating insulin target tissues such as hyperosmolarity or amino acid deprivation are associated with insulin resistance; blockage of the cell volume response to insulin may be the common denominator in dehydration-induced insulin resistance (4).

As a consequence of dehydration, the blood–brain barrier permeability is altered by serotonergic and dopaminergic systems, potentially causing central nervous system dysfunction if dehydration is prolonged (7).  

Understanding Scientific Research [2]: Experimental vs. Observational Studies

Not all scientific studies are created equal. There are several types of studies, and  the first distinction is between experimental and observational evidence.

Previously I posted about how to read a study and how a study is structured with different sections. Certain features in each section should be present and be clear. For example, in the discussion section results should be put into context of the overall or similar literature and weighed against it. 

Scientific evidence should be used to figure out what is more likely to be true, and not misused to defend what we want to be true, for whatever reason.

In this day and age, scientific beliefs and (provisional) conclusions must be based on solid evidence. But what constitutes solid evidence? This can be a tricky question because we have several kinds of evidence with different strengths and weaknesses. This alone makes it all more difficult to interpret.

We must be able to recognize what we are looking at and how to distinguish between different types of scientific evidence. Some studies have more weight than others.

Successful Dieting [5/5]: What Is The Best Weight Loss Rate?

The composition of weight loss is important. While greater deficits yield faster weight loss, this strategy makes you lose more lean body mass than slower weight loss programs due to the size of the caloric deficit, and dietary factors. For example, resistance exercise or high protein diets may modify the proportion of weight loss resulting from body fat versus lean tissue (1,2,3).

Lean body mass is lost in concert with body fat during weight loss (4,5). As the size of the caloric deficit increases weight loss coming from lean body mass also tends to increase (6,7,8). 

As I have argued before, not all diets can be considered successful, the importance of keeping lean body mass loses to a minimum during a diet is paramount. That is, the ratio of body fat to lean mass should be high, for example 80% of fat mass to 20% of lean mass.

Gluten Digestion and the Microbiome: Gluten-Eating Bacteria

It is often assumed, and sometimes defended fanatically by certain “groups”, that humans cannot digest gluten, and therefore no single human (with or without CD) should be eating gluten-containing foods, such as wheat. For them the story ends here. But there is a lot more to it.


There is a large variety of bacteria capable of digesting gluten with gluten-degrading proteases naturally present in the upper human gastro-intestinal tract. The oral cavity is colonised with microorganisms that produce proteases capable of hydrolysing peptides rich in proline and glutamine residues. Intestinal dysbiosis is present in celiac disease patients, characterized by increased Gram-negative bacteria, other potentially pro-inflammatory bacteria and reduced bifidobacteria.

Small-intestinal bacterial overgrowth (SIBO) and infections have been suggested to contribute to CD pathogenesis with persistence of gastrointestinal symptoms after gluten withdrawal. Pathogenic enterobacteria could play a role in the switch from tolerance to an inflammatory immune response to gluten, by altering the permeability of the intestinal mucosa.

A lack of maturation of the gut microbiota is observed within the first 2 years of life in infants at risk of CD. The early introduction of gluten and the lack of maturity in the GI microbiota could trigger or accelerate the development of autoimmunity. Bacterial groups related to gluten metabolism are altered in patients with CD.

Either Bifidobacterium could protect against CD, or inherent features of the CD intestine influence Bifidobacterium colonization. Reduced IgA-coated bacteria is associated with intestinal dysbiosis suggesting the existence of a barrier defect, which fails to stabilize the gut microbiota and prevent the host from the invasion of harmful antigens and pathogens.

The induction of gliadin proteolysis in the human gut might not be the solution but the origin of CD, since gliadinases are CD specific. Gliadinases might have a bacterial origin within the duodenum of patients with CD. Gliadin-metabolising bacteria could be absent, or present to a much lower degree, in the duodenum of all non-predisposed individuals.

In CD the mucosal tolerance to the gut microbiota is deregulated. Reductions in beneficial Gram-positive bacteria could favor the residence and interactions of harmful Gram-negative bacteria within the mucosal surface thereby contributing to loss of gluten tolerance.

Either a particular glycosylation pattern in predisposed individuals favors harmful bacterial adhesion, which contributes to CD pathogenesis or modifications in the composition of the intestinal microbiota lead to alterations in the glycosylation pattern and its defensive role of the mucus layer against infections and CD.

Read the Free Full Article @ and learn a ton about gluten with myself and Brad Dieter, PhD 

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Summary of 34 articles with 36.528 words and 1121 references on
Exercise and nutrition

Successful Dieting [4/5]: How Much Carbohydrate? (with or without exercise)

A practical carbohydrate threshold appears to exist where further reductions negatively impact performance and put one at risk for LBM losses. Find out how much carbs you need in a diet.

Food Allergy: Soy (less allergenic than egg, milk, wheat and peanut)

Not all food are allergenic, and not all allergenic foods are equally allergenic. In other words, foods vary in clinical allergy significance. Generally speaking, all food proteins are potentially allergenic for some people. Among all foods, 8 foods accounts for 90% of food allergies: milk, wheat, peanuts, tree nuts, eggs, fish, crustacea, and soy (1).

Soy proteins tend to be less immunologically reactive than many other food proteins.

Immunology of food allergy

Type I food allergy consists of 3 steps (2,3,4,5). First there is a sensitization starting with food antigens moving across the intestinal barrier. An immature gut, or infection will worsen the process. Antibody responses are triggered (IgG and IgA) leading to an allergic response.

Food antigens activate antigen-specific B cells and helper T cells that direct B cells to differentiate into IgE-producing plasma cells. IgE is then quickly bound by high-affinity IgE receptors mainly on the surface of mast cells. Mast cells contain large amounts of histamine which is a main inducer of symptoms of allergy. Following this insult, a large number of mast cells armed with IgE antibodies is present in circulation and tissues.

After sensitization, allergen or multivalent allergen fragments are again absorbed after ingestion. IgE antibodies on mast cells bind the allergen so that the allergen cross-links at least 2 receptor-bound IgE molecules. This sends a signal causing the mast cell to release histamine and other inflammatory mediators (degranulation). Timing and magnitude of the release is defined by allergen dose and a number of poorly understood host factors. At the end, clinical symptoms ensure when histamine and other inflammatory mediators stimulate the wide variety of allergic symptoms in other cells and organs.

The Occupational Health of Santa

Santa Claus appears to have been an older man since at least the 1930s, works long hours and traverses multiple time zones in the course of delivering presents to children in all parts of the world (1). For these reasons it should be acknowledged that unique occupational hazards exist for Santa Claus. 

Close examination of the working conditions of Santa Claus highlights a number of pertinent occupational health issues (1). There is no standardized requirement for Santa to have a medical check-up, other than pre-employment drug screening (1,2).

Understanding Scientific Research [1/2]: How to Read a Study and Interpret Results

A skeptical mind is always aware that scientific research is progressive, and that new findings are constantly emerging and can be used to change the way things are. The ability to interpret and evaluate research in context is critical in the process and understanding the results.

All studies depend on their own context. This is a crucial point and the reason why the public can be confused by contradicting studies and in some extreme cases distrust or reject science altogether. For example, 2 studies that apparently contradict each other can both be valid, under different circumstances.

Successful Dieting [3/5]: Calorie Restriction, Higher Protein, Exercise and Recomposition

We have seen before that higher protein diets and exercise, especially weight training have additive effects on lean body mass maintenance or even gain of lean body mass in a caloric deficit. Higher protein diets and supplemental exercise tends to increase weight loss, but has greater effects on body composition through the preservation of lean body mass while increasing fat loss.

Successful Dieting [2/5]: Protein Intake

A large volume of human clinical data supports increased dietary protein for favorable changes to body composition.

One systematic review concluded that in studies where a higher protein intervention was deemed successful there was, on average, a 58.4% g/kg/day between group protein intake spread versus a 38.8% g/kg/day spread in studies where a higher protein diet was no more effective than control (1). The average change in habitual protein intake in studies showing higher protein to be more effective than control was +28.6% compared to +4.9% when additional protein was no more effective than control (1).

Successful Dieting [1/5]– Lean Body Mass and The Importance of Exercise

Not all weight loss should be considered successful. A successful weight loss should be judged taking into account several factors such has the ratio of fat to lean mass lost - in other words, in a successful diet lean mass losses should be kept to a minimum. Exercise, especially weight training, can and should be used to offset lean mass losses during a diet, and in some cases make you lose fat and gain muscle at the same time.

AARR – The effects of nutrition and exercise on sleep Part 3/3: Exercise and sleep


Physical activity alters endocrine, autonomic nervous system (ANS), and somatic functions, therefore daytime exercise should affect sleep. The somatic physiology effects of exercise can result in persistent effects and serve as a robust stimulus to affect sleep’s physiological mechanisms. Appropriate amounts of exercise could alter those mechanisms in a preferable direction.

Factors such as exercise type, intensity, timing, subjects, and differences between acute and chronic exercise all have different effects on sleep. Exercise influence sleep by increasing total sleep time and prolonging REM latency, decreasing REM sleep and increasing SWS. Exercise has the ability to induce circadian phase-shifting effects perhaps as potent as bright light.

An important distinction between acute and chronic exercise effects on sleep is that chronic exercise substantially changes somatic functions in ways one bout of exercise does not, such as long-term improvements in body composition, basic metabolic rate, cardiac function, glycemic control, immune function and exercise also improves mood state.

Results from several studies indicate that most athletes from several sports are sleep deprived and obtain between 5-7h of sleep per night. One factor that may contribute to the low habitual sleep duration observed in athletes is their training schedule. Sleep/wake behavior in athletes depends on the time of day that they are required to train. For example, training in the early morning can be detrimental, evening exercise is not associated with worse sleep and vigorous late-night exercise does not disturb sleep quality. The effects of exercise on sleepiness are most pronounced when exercise is performed in the middle of the night.

Several other factors that can influence sleep, such as anxiety during intensive training which interfere with sleep onset; hydration programs that can increase the frequency of toilet visits; and muscle soreness and physical discomfort associated with high-intensity training that can also disturb sleep.

Exercise by increasing alertness and releasing different neurochemical substances during its realization can mask the effects of sleep deprivation when it occurs simultaneously. This could be effective for athletic performance if levels of perceived effort are decreased by exercise in a sleep deprived state.

Potential interventions for increasing sleep duration in sleep deprived athletes are discussed. Exercise can be used strategically to improve sleep, possibly aid in sleep deprivation, and induce phase-shifts in sleep in jet lag conditions.

AARR, November 2016
4680 words, 91 references
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Summary of 34 articles with 36.528 words and 1121 references on
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