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Background:Sarcopenia (SA) is a progressive skeletal muscle disorder, associated with increased risk of adverse outcomes, including falls, fractures, physical disability and mortality. Several risks factors may contribute to the development of SA in the elderly; among them, nutrition plays a key role in muscle health. The elderly are at risk of inadequate intake in terms of micronutrients affecting muscle homeostasis, such as B vitamins, related to homocysteine (Hcy) metabolism.Objectives and methods:This narrative review analysed the association between increased Hcy levels and SA, according to the criteria of the International Working Group on Sarcopenia, the European Working Group on Sarcopenia in Older People and the Asian Working Group for Sarcopenia. The authors focused not only on SA per se but also on exploring the association between increased Hcy levels and components of SA, including muscle mass, muscle strength and physical performance.Results:Results are inconsistent, except for muscle mass, showing no significant associations with Hcy levels.Conclusions:Few and conflicting data emerged in this review on the association between SA and increased Hcy levels due to numerous differences between studies that change the significance of the association of Hcy and SA, as well as the muscle strength, muscle mass and physical performance. Furthermore, because the ageing process is not uniform in the population owing to differences in genetics, lifestyle and general health, chronological age fails to address the observed heterogeneity among the ‘elderly’ of the studies reported in this revision. Therefore, further studies are still needed.

This review aims to define the effectiveness of the ketogenic diet (KD) for the management of sarcopenic obesity. As the combination of sarcopenia and obesity appears to have multiple negative metabolic effects, this narrative review discusses the effects of the ketogenic diet as a possible synergic intervention to decrease visceral adipose tissue (VAT) and fatty infiltration of the liver as well as modulate and improve the gut microbiota, inflammation and body composition. The results of this review support the evidence that the KD improves metabolic health and expands adipose tissue γδ T cells that are important for glycaemia control during obesity. The KD is also a therapeutic option for individuals with sarcopenic obesity due to its positive effect on VAT, adipose tissue, cytokines such as blood biochemistry, gut microbiota, and body composition. However, the long-term effect of a KD on these outcomes requires further investigations before general recommendations can be made.

The purpose of the present study was to evaluate the Pearson correlations between hemodynamic parameters obtained with near infrared spectroscopy (NIRS), namely total hemoglobin (tHb) and tissue oxygen index (TOI %), as indicators of blood flow and oxygen extraction, and myoelectric parameters obtained with surface multichannel electromyography (sEMG), namely fractal dimension (FD) and conduction velocity (CV) slopes, as descriptors of central and peripheral fatigue, during sustained high level isometric contractions at 60% maximal voluntary contraction (MVC), in elderly subjects. Ten recreationally healthy elderly subjects (age 67.7 ± 4.6 years), 5 males and 5 females, performed one isometric contraction of the elbow flexors at 120° joint angle at 60% of MVC until exhaustion in two subsequent trials 1 week apart, one for the sEMG and the other one for NIRS recordings from the biceps brachii. A negative strong Pearson’s correlation between TOI % slope in the functional hyperemic phase (HP) of contraction and a positive correlation between the slope of TOI % recorded during the ischemic phase (IP) and the CV slope were found (r = − 0.76, P

Purpose In facioscapulohumeral muscular dystrophy (FSHD) fatigue is a major complaint. We aimed to investigate whether during isometric sustained elbow flexions, performance fatigability indexes differ in patients with FSHD with respect to healthy controls. Methods Seventeen patients with FSHD and seventeen healthy controls performed two isometric flexions of the dominant biceps brachii at 20% of their maximal voluntary contraction (MVC) for 2 min and then at 60% MVC until exhaustion. Muscle weakness was characterized as a percentage of predicted values. Maximal voluntary strength, endurance time and performance fatigability indices (mean frequency of the power spectrum (MNF), muscle fiber conduction velocity (CV) and fractal dimension (FD)), extracted from the surface electromyogram signal (sEMG) were compared between the two groups. Results In patients with FSHD, maximal voluntary strength was 68.7% of predicted value (p p r = 0.62) and lower levels of performance fatigability, characterized by reduced rate of changes in MNF (p r = 0.56), CV (p p r = 0.51) and increased endurance time (p r = 0.63), during the isometric contraction at 60% MVC. Conclusion A decreased reduction in the slopes of all the considered sEMG parameters during sustained isometric elbow flexions suggests that patients with FSHD experience lower levels of performance fatigability compared to healthy controls.

Oil flow distribution in the winding has a direct impact on the cooling performance. In addition, static pressure drop over the winding determines oil split among windings connected hydraulically in parallel. In this paper, experimental verifications are provided to support computational fluid dynamics (CFD) simulations for disc-type windings in oil forced and directed (OD) cooling modes. Oil flow distribution in and pressure drop over disc-type winding models are measured using a particle image velocimetry (PIV) system and a differential pressure instrument, respectively. Dimensional analysis is adopted to analyze the relationship between flow distribution, or pressure drop, and the controlling parameters. CFD parametric sweeps of the dimensionless parameters obtained from the dimensional analysis are conducted and the CFD results are then correlated with the dimensionless parameters. The comparisons between measured results and the corresponding results obtained from the correlations demonstrate constant consistency, proving the validity of both the method of dimensional analysis and the correlations. Finally, comparisons of experimental results from isothermal and nonisothermal conditions in OD cooling modes are executed, which show that the isothermal conclusions can be extended to nonisothermal cases because the effects of buoyancy force and hot-streak dynamics are proved to be negligible.

Dates have a low glycemic index and are a source of antioxidants but, nevertheless, contain more than 70% sugar. This study aims to assess the effects of date consumption (three dates daily) on glycemic profile (HbA1c), body mass index (BMI), quality of life, and lipid profile, including total cholesterol, triglyceride, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) in terms of safety for type 2 diabetic mellitus (T2DM) subjects. A randomized controlled trial was conducted with a sample of 100 T2DM subjects (39 male and 61 female) randomly assigned in two groups. The first group received three dates daily for 16 weeks, and the control group avoided date consumption. After a 16-week follow-up period, the study results showed an improvement of lipid profile with a statistically significant decrease in total cholesterol of ∆ = &minus, 0.209 mmol/L (confidence interval (CI) 95% &minus, 0.358, &minus, 0.059, p &lt, 0.05) and in LDL of ∆ = &minus, 0.171 mmol/L (CI 95% &minus, 0.358, 0.016) in the group receiving three dates daily. Intra-group mean differences of BMI were not statistically different in both groups after 16 weeks of date consumption. Even HbA1c did not change, both within and between groups after date consumption (∆ = 0.087%, CI 95% &minus, 0.086, 0.261). Between groups, mean difference changes (intervention minus control) showed a statistically significant improvement of quality of life index of ∆ = &plusmn, 30.66 points (CI 95% 12.45, 48.23) due to the consequent improvement in mental health. Although the definitive effect of dose/intake response of date consumption on Hb1Ac, lipid profile, and BMI in T2DM subjects is still to be established, the study suggests that dates could potentially have a beneficial effect on lipid profile, especially in reducing total cholesterol and elevating HDL, because of its high polyphenolic content. In addition, a low&ndash, moderate consumption of dates did not impact glucose levels because of dates&rsquo, low glycemic index.

The topic of creatine supplementation has received considerable attention for more than two decades, and it is likely to get even more attention, given that creatine plays such an essential role in skeletal muscle physiology. Creatine is an endogenous guanidine compound, which is synthesized starting from three amino acids ( methionine , glycine , and arginine ), able to influence muscle biochemical processes involved in energy production and recovery from exercise. In several experimental conditions the potential of creatine supplementation on anaerobic and aerobic performance has been extensively established. Other evidence suggests that creatine may exert beneficial effects to increase muscle hypertrophy and to reduce muscle damage by regulating various mechanisms, such as muscle fiber gene expression, inflammatory response, oxidative stress, calcium homeostasis, and satellite cell activity. The goal of this chapter is to examine the results of existing studies on creatine supplementation and its role on skeletal muscle physiology in healthy humans.

To counteract muscle mass, muscle strength and power loss during aging, and to study age-related change of neuromuscular manifestation of fatigue in relation to nutritional supplementation.randomized controlled double-blind study.Twice-daily consumption for 12 weeks of an Essential Amino Acids (EAA)-based multi-ingredient nutritional supplement containing EAA, creatine, vitamin D and Muscle Restore Complex®.38 healthy elderly subjects (8 male, 30 female; age: 68.91±4.60 years; body weight: 69.40±15.58 kg; height: 1.60±0.09 m) were randomized and allocated in supplement (SUPP) or placebo (PLA) group. Mean Measurements: Vitamin D blood level; Appendicular Lean Mass (ALM); Visceral Adipose Tissue (VAT); Maximal Voluntary Contraction (MVC) and Peak Power (PP); myoelectric descriptors of fatigue: Fractal Dimension and Conduction Velocity initial values (FD iv, CV iv), their rates of change (FD slopes, CV slopes) and the Time to perform the Task (TtT). Mean Results: Significant changes were found in SUPP compared to baseline: Vitamin D (+8.73 ng/ml; p0.001); ALM (+0.34 kg; p0.001); VAT (-76.25 g; p0.001); MVC (+0.52 kg; p0.001); PP (+4.82 W; p0.001). Between group analysis (SUPP Vs. PLA) showed improvements: vitamin D blood levels (+11,72 ng/ml; p0.001); Legs FFM (+443.7 g; p0.05); ALM (+0.53 kg; p0.05); MVC (+1.38 kg; p0.05); PP (+9.87 W; p0.05). No statistical changes were found for FD iv, CV iv, FD and CV slopes and TtT, either compared to baseline or between groups. Significant correlations between mean differences in SUPP group were also found.The study demonstrates that in healthy elderly subjects an EAA-based multi-ingredient nutritional supplementation of 12 weeks is not effective to change myoelectric manifestation of fatigue and TtT failure but can positively affect muscle mass, muscle strength, muscle power and VAT, counterbalancing more than one year of age-related loss of muscle mass and strength.

Background: The purpose of this study was to investigate the acute effects of a single oral administration of an essential amino acids enriched mixture (EAA) on myoelectric descriptors of fatigue and maximal force production after a resistance exercise protocol (REP).Methods: Twenty adult males (age: 27 ± 6 years; body mass: 72.7 ± 7.50 kg; height: 1.76 ± 0.06 m) were enrolled in a double-blind crossover placebo-controlled study. Subjects were randomized to receive EAA mix (0.15 g/kg BM) or a placebo (PLA) in two successive trials 7 days apart. In both trials subjects completed a REP 2 h after the ingestion of the EAA mix or PLA. Before ingestion and after REP subjects performed isometric contractions of the dominant upper limb with the elbow joint at 120 degrees: (1) two maximal voluntary contractions (MVCs) for 2–3 s; (2) at 20% MVC for 90 s; (3) at 60% MVC until exhaustion. Mean values of MVC, conduction velocity initial values (CV), fractal dimension initial values (FD), their rates of change (CV slopes, FD slopes) and the Time to perform the Task (TtT) were obtained from a multichannel surface electromyography (sEMG) recording technique. Basal blood lactate (BL) and BL after REP were measured.Results: Following REP a significant decrease of MVC was observed in PLA (P < 0.05), while no statistical differences were found in EAA between pre-REP and post-REP. After REP, although a significant increase in BL was found in both groups (P < 0.0001) a higher BL Δ% was observed in PLA compared to EAA (P < 0.05). After REP, at 60% MVC a significant increase of CV rate of change (P < 0.05) was observed in PLA but not in EAA. At the same force level TtT was longer in EAA compared to PLA, with a significant TtT Δ% between groups (P < 0.001).Conclusion: Acute EAA enriched mix administration may prevent the loss of force-generating capacity during MVC following a REP. During isometric contraction at 60% MVC after REP the EAA mix may maintain CV rate of change values with a delay in the TtT failure.

Background : Fish protein hydrolysates (FPHs) have been reported as a suitable source of proteins for human nutrition because of their balanced amino acid composition and positive effect on gastrointestinal absorption. Objective : Here, we investigated the effect of a FPH, Slimpro ® , obtained from blue whiting ( Micromesistius poutassou ) muscle by enzymatic hydrolysis, on body composition and on stimulating cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1) secretion. Design : A randomized clinical study was carried out on 120, slightly overweight (25 kg/m 2 ≤ BMI

In this paper, numerical investigation of oil flow distribution and temperature distribution is performed for a disc-type transformer winding in an oil natural (ON) cooling mode. First, dimensional analysis is carried out based on the governing differential equations with the Boussinesq approximation, and Re, Ri and Pr are found to be the governing dimensionless parameters in determining flow and temperature distribution. Then a CFD case study is performed on a winding model as the benchmark for this study, in which reverse flow and hot-plumes are observed. After the case study, CFD parametric sweeps of Re and Ri are executed. It is found that the minimum value of the hot-spot factor, which characterizes the thermal performance of the transformer winding, is achieved in a relatively small and fixed range of Ri (from 0.4 to 0.6) regardless of the values of Re and Pr in their practical ranges. Consequently, the relationship of an invariable minimum hot-spot factor with a small fixed range of Ri makes the optimization of the transformer operational regime possible. Finally, a new CFD case study is performed to confirm the shifting of an uncontrolled operational regime to a quasi-optimal one by changing Ri from 1.46 in the benchmark case to 0.6 in the new case.

In this paper, dimensional analysis is adopted to study fluid flow distribution and temperature distribution in disc-type ON (oil natural) cooled transformer windings. Theoretical analysis on the thermal driving force and the pressure drop in the liquid circulation loop is also performed to determine the total liquid flow rate in the transformer. The thermal performance of three different liquids, a hydrocarbon mineral oil, a hydrocarbon gas-to-liquid (GTL) oil and a synthetic ester are investigated using computational fluid dynamics (CFD) simulations, based on the understanding from dimensional analysis and the flow rates determined from the theoretical analysis. It is found in the investigated conditions that the hydrocarbon mineral and GTL oil share similar thermal performance; the synthetic ester has a lower total flow rate due to its higher viscosity and therefore requires additional effort to improve the thermal performance.

The term doping is generally used to indicate practices based on the use of performance-enhancing drugs (PEDs) or the abuse of medical therapies. Mostly analysed by doctors and officials, doping nevertheless also requires a philosophical consideration to avoid being simplistically portrayed as an isolated practice. To do this, we need to pay attention to the contradictions and paradoxes in the modern approach to doping in sport. In this context, doping is not only relevant to the health of an individual involved in the violation of World Anti-Doping Agency (WADA) criteria, but it actually represents a double-edged phenomenon containing ethical and legal points of view. Several philosophical items affect the ethics of doping. While, indeed, through a deontological vision it is easy to morally condemn an athlete who takes the decision to turn to doping, the same condemnation becomes difficult when the practice of doping is compared with the strong social demand of winners in every field of life. This point must be considered to prevent doping from becoming accepted as a daily practice to excel at all costs and regarded not only as normal but as a necessity for those participating in sport at both an amateur and professional level. Furthermore, a complete discussion on doping has to consider not only the philosophy of performance-enhancing drug abuse, but also the widespread practice of an inappropriate and excessive intake of certain dietary supplements with the unique and obsessive purpose (similar to doping) of increasing physical or mental performance. Based on the above, the aim of this paper is to provide a critical opinion of the doping problem and its related practices and analyze possible solutions considering issues that go beyond the impact of doping on health and reflect on whether it is right or not that an athlete does all he can to improve his performance.

This systematic review aimed to investigate the association of fish and sea fish dietary patterns (FishDiet) and meat or processed meat dietary patterns (MeatDiet) with bone mineral density (BMD) and/or risk of fractures (RF). This review includes 37 studies with a total of 432,924 subjects. The results suggest that MeatDiet and FishDiet did not affect BMD or RF in 48.2% of the subjects with MeatDiet and in 86.5% of the subjects with FishDiet. Positive effects on bone were found in 3% of subjects with MeatDiet and in 12% with FishDiet. Negative effects on bone were observed in 2.7% of FishDiet and in 47.9% of MeatDiet. Major negative effects of MeatDiet were found in subjects located in the Netherlands, Greece, Germany, Italy, Norway, UK and Spain who do not sustain a Mediterranean diet (92.7%); in Korea (27.1%); in Brazil and Mexico (96.4%); and in Australia (62.5%). This study suggests that protein intake from fish or meat is not harmful to bone. Negative effects on bone linked to FishDiet are almost null. Negative effects on bone were associated to MeatDiet in the setting of a Western Diet but not in Mediterranean or Asian Diets.

Beef is a nutrient-rich, high-quality protein containing all the essential amino acids in proportions similar to those found in human skeletal muscle. In order to investigate the efficacy of a beef supplementation strategy on strength and body composition, we recruited 26 young healthy adults to participate in a resistance-training program of eight weeks, based on the use of isotonic machines and free weights at 75% of one repetition maximum. Subjects were randomly divided into two groups, food group and control group, of 12 and 14 subjects respectively. Food group were supplemented after resistance training with a 135 g serving of lean beef (tinned meat), providing 20 g of protein and 1.7 g of fat. No supplementation was provided to control group. Fat mass, fat free mass, lean mass, assessed by bioelectrical impedance analyzer, and muscle strength, assessed by one repetition maximum test, were evaluated in all subjects both at the beginning (week 0) and at the end (week 8) of the study. Pre- and post-training differences were evaluated with paired t-tests while group differences for each outcome parameter was evaluated with independent t-tests. At the end of the study the food group showed a significantly decrease in fat mass (week 0: 15.0 ± 6.7 kg; week 8: 13.1 ± 7.6 kg; Δ: −1.9 ± 2.9 kg; p < 0.05) and a significantly increase in fat free mass (week 0: 52.8 kg ± 9.4; week 8: 55.1 kg ± 10.9; Δ: 2.3 ± 2.5 kg; p < 0.01). No significant differences in lean mass were found in either food group or control group. No significant differences in one repetition maximum tests were found between food group and control group. Tinned meat can be considered a nutrition strategy in addition to other proteins or amino acid supplements, but as with any other supplementation strategy, a proper nutrition plan must be coupled.

Despite the numerous positive effects of physical exercise, some negative physiological changes occur in long-lasting heavy training with transient dysfunction of the immune system, increased inflammation, and oxidative stress. This is the case of elite athletes, who train intensively to compete at the highest levels. However, these athletes can counteract the negative effects of heavy training, reducing acute and chronic inflammations and supporting the immune system, with nutritional and supplementation countermeasures. For this purpose, macronutrient manipulation with an appropriate use of certain supplements can be considered as an intervention to reduce exercise-induced immune changes and inflammatory risk. For example, branched-chain amino acid (BCAA) supplementation may promote such immune responses in skeletal muscle. Furthermore, micronutrients play an important role in immune function; in particular, the antioxidant capacity of several dietary micronutrients (e.g., tocopherols, docosahexaenoate, and flavonoids) is very interesting to support the endogenous antioxidant defense systems of the athletes, counterbalancing the negative effects of oxidative damage due to free radicals. Some of these nutrients have potential anti-inflammatory properties as assessed by the attenuated levels of interleukin-6 (IL-6) and C-reactive protein (CRP). Key Teaching Points: Long-lasting heavy training plan and competition can lead to chronic immune suppression in athletes, increasing infection risk. Chronic exercise increases mobilization of neutrophils, decreases mobilization of lymphocytes, and decreases the absolute and relative numbers of neutrophils at rest. Nutritional deficiencies alter the immuno-system and increase infection risk. Nutrition can influence exercise-induced immune suppression. Elite athletes competing at the highest levels can benefit from nutritional and supplementation support to improve immunity and reduce acute and chronic inflammations.

Aging is an inevitable biological process, characterized by a general decline in physiological and biochemical functions of major body systems. In the case of the neuromuscular system, reductions in strength and mobility cause a deterioration in motor performance, impaired mobility, and disability. At the cellular level, aging is caused by a progressive decline in mitochondrial function that results in accumulation of reactive oxygen species (ROS). As the level of oxidative stress in skeletal muscle increases with age, advancing age is characterized by an

As we age, the aerobic and functional capacities of our major physiological systems progressively decline. In the case of the neuromuscular system, reductions in strength and mobility cause a deterioration in motor performance and in turn a greater tendency to fall (with increased risk of fractures), impaired mobility, disability and loss of independence in the elderly. Given the increase in our life expectancy and the consequent growth in the elderly population, these conditions will have an increasing impact on modern healthcare systems, and their prevention and attenuation needs to be addressed. Several intervention strategies have been used to improve motor performance among the aging. At the cellular level, aging is caused by a progressive decline in mitochondrial function that results in the accumulation of reactive oxygen species (ROS) generated by the addition of a single electron to the oxygen molecule As the level of oxidative stress in skeletal muscle increases with age, the production of some antioxidant enzymes increases adaptively to compensate in part. The aging process is characterized by an imbalance between an increase in the production of reactive oxygen species in the organism and the antioxidant defences as a whole. The goal of this review is to examine the results of existing studies on oxidative stress in aging human skeletal muscles, taking into account different physiological factors (sex, fiber composition, muscle type and function).