Effect of resistance training on quadriceps femoris muscle thickness obtained by ultrasound: A systematic review with meta-analysis.

OBJECTIVE: The present study aimed to determine the magnitude and intervention time of resistance training required to generate adaptations in the muscle thickness of the quadriceps muscle obtained by ultrasound in healthy adults. METHOD: A systematic review with meta-analysis was conducted on studies recovered from Pubmed, Web of Science, and Scopus databases up to March 2022. The study selection process was carried out by two independent researchers, with the presence of a third researcher in case of disagreements. The methodological quality of the studies was determined with the TESTEX scale, and the risk of bias analysis was determined using Cochrane's RoB 2.0 tool. The meta-analysis used the inverse of the variance with a fixed model, and the effect size was reported by the standardized mean difference (SMD) with a confidence interval of 95%. RESULTS: Ten studies were included in a meta-analysis. The overall analysis of the studies demonstrated an SMD = 0.35 [95% CI: 0.13-0.56] (P = 0.002), with a low heterogeneity of I2 = 0% (P = 0.52). No publication bias was detected using a funnel plot followed by Egger's test (P = 0.06). The degree of certainty of the meta-analysis was high using the GRADE tool. CONCLUSION: We found that resistance training can generate significant average increases of 16.6% in muscle thickness obtained by ultrasound in the quadriceps femoris muscles of healthy adults. However, the subgroup analysis showed that significant effect sizes were only observed after eight weeks of training.

Effects of Beetroot-Based Supplements on Muscular Endurance and Strength in Healthy Male Individuals: A Systematic Review and Meta-Analysis.

The aim of this study was to systematically review the current literature and analyze the effects of beetroot-based supplements (BRS) on muscular performance. Randomized controlled trials that assessed the acute or short-term effects of BRS administration on muscular endurance and/or strength in healthy male individuals were retrieved from PubMed, EMBASE, CENTRAL, and Web of Science databases from inception to February 20th, 2023. In addition, we also searched preprint papers in medRxiv.org, bibRxiv.org; thesis and dissertations included in oatd.org; and clinical trials published in ClinicalTrials.gov. Data extraction, risk of bias, and study quality were assessed by 2 authors. Meta-analyses and subgroup analyses of standardized mean differences (SMD) were performed using a random-effects model. A total of 1486 records were identified in the databases and 2 were obtained by manual search in the reference list. Of those, 27 studies attended eligibility criteria and composed this systematic review. BRS administration resulted in a positive effect on muscular endurance (SMD: 0.31; 95% confidence interval (CI): 0.10 to 0.51; p < 0.01; n = 16 studies). There was an overall significative effect for muscular strength (SMD: 0.26; 95% CI: 0.03 to 0.48; p < 0.05; n = 18 studies), but a subgroup analysis showed that significant effects were found when strength was measured in a fatigued (SMD: 0.64; 95% CI: 0.25 to 1.03; p < 0.01), but not resting state. BRS administration have a small ergogenic effect on muscular endurance and attenuate the decline in muscular strength in a fatigued state in healthy male individuals.

Beetroot-based supplements can improve muscular endurance and attenuates the decline in muscular strength. These effects are attributed to the inorganic nitrate contained in these products, which ranged from 316­985 mg/day, ingested 2­3 hours before exercise.Beetroot-based supplements administration can generate a modest increase in the number of repetitions performed to failure or in exercise time to exhaustion, which may contribute to the performance and optimization of the results of people involved in isotonic exercises (e.g., resistance training).Beetroot-based supplements ingestion can improve muscular strength, particularly it aids in the recovery of muscular strength after a fatiguing task.

Validity, reliability and measurement error of quadriceps femoris muscle thickness obtained by ultrasound in healthy adults: a systematic review / Validade, confiabilidade e erro da medida da espessura muscular do quadríceps femoral obtida pela ultrassonografia em adultos saudáveis: uma revisão sistemática

Abstract Due to its low cost and operational simplicity, ultrasound has been used to monitor muscle thickness in laboratory environments, rehabilitation clinics, and sports clubs. However, it is necessary to determine the measurement's quality to infer whether the possible changes observed are derived from the treatment or the measurement error. Therefore, we performed a systematic review to determine the validity, reliability, and measurement error of quadriceps femoris muscle thickness obtained by ultrasound in healthy adults. A search was conducted in the Pubmed, Scopus, and Web of Science databases until April 2022. The study selection process was carried out by two independent researchers, with the presence of a third researcher in case of disagreements. Twenty-six studies were eligible for the review, being 4 of validity, 4 of reliability only, and 18 of reliability and measurement error. The intraclass correlation coefficient ranged from 0.60 to 0.99 in validity studies and from 0.44 to 0.99 in reliability studies. The typical error of measurement ranged from 0.01 to 0.47 cm, and the coefficient of variation was from 0.5 to 17.9%. Four studies received "very good" classification in all the risk of bias analysis criteria. Therefore, it is concluded that the quadriceps femoris muscle thickness obtained by ultrasound was shown to be valid, reliable, and to have low measurement errors in healthy adults. The weighted average of the relative error was 6.5%, less than typical increases in resistance training studies. The raters' experience and methodological care for repeated measurements were necessary to observe low measurement errors.

Resumo Devido ao baixo custo e simplicidade operacional, a ultrassonografia tem sido utilizada para monitorar a espessura muscular em ambientes laboratoriais, clínicas de reabilitação e clubes desportivos. Porém, é necessário determinar a qualidade da medida para inferir se as possíveis modificações observadas são decorrentes do tratamento ou do erro da medida. Portanto, realizamos uma revisão sistemática para determinar a validade, confiabilidade e erro da medida da espessura muscular do quadríceps femoral obtida pela ultrassonografia em adultos saudáveis. Foi realizada busca nas bases de dados Pubmed, Scopus e Web of Science até abril de 2022. O processo de seleção dos estudos foi realizado por dois pesquisadores independentes, com a presença de um terceiro pesquisador em caso de divergências. Vinte e seis estudos foram elegíveis para a revisão, sendo 4 de validade, 4 apenas de confiabilidade e 18 de confiabilidade e erro de medida. O coeficiente de correlação intraclasse variou de 0,60 a 0,99 em estudos de validade e 0,44 a 0,99 em estudos de confiabilidade. O erro típico da medida variou de 0,01 a 0,47 cm e o coeficiente de variação foi de 0,5 a 17,9%. Quatro estudos receberam classificação "muito bom" em todos os critérios na análise de risco de viés. Portanto, concluiu-se que a espessura muscular do quadríceps femoral obtida pela ultrassonografia se mostrou válida, confiável e com baixos erros de medida em adultos saudáveis. A média ponderada do erro relativo foi de 6,5%, menor do que os aumentos típicos em estudos de treinamento resistido. A experiência dos avaliadores e o cuidado metodológico com as medidas repetidas foram necessários para observar baixos erros de medida.

Acute Effects of L-Arginine Supplementation on Oxygen Consumption Kinetics and Muscle Oxyhemoglobin and Deoxyhemoglobin during Treadmill Running in Male Adults.

L-arginine is used as a nitric oxide related supplement intended to improve sports performance, and to enhance muscular recovery during exercise. However, the literature is inconclusive. The aim of this study was to determine the effects of acute oral L-arginine supplementation on O2 consumption kinetics and local muscle blood volume and oxygenation during treadmill running at two different intensities. Using a double-blind, crossover and placebo-controlled design, 11 young healthy male adults were randomly assigned to 6 g of L-arginine (ARG) or placebo (PLA) supplementation that was ingested 60 min before the exercise test. Tests consisted of treadmill run at two different intensities (5 min each; moderate, 90% of ventilatory threshold, VT; and heavy, 50% of the difference between VT and VO2peak) interspersed by 1-min walking. Respiratory gas exchange variables were measured continuously with an automated metabolic cart. Near infrared spectroscopy (NIRS) was used to continuously monitor muscle oxyhemoglobin and deoxyhemoglobin and total hemoglobin. Blood samples were collected before supplementation and 6 min after exercise. Two-way repeated measures ANOVA did not show differences in plasma nitrite concentrations between ARG or PLA conditions during the running tests. No significant differences were observed between ARG and PLA conditions for O2 kinetics as well as for NIRS variables. ARG supplementation does not improve physiological responses associated with oxygen cost and NIRS variables during running treadmill tests. Hence, our results do not support the use of L-arginine as an ergogenic aid for running performance in young healthy males.

Acute supplementation of L-arginine affects neither strength performance nor nitric oxide production.

BACKGROUND: L-arginine is a semi-essential amino acid involved in nitric oxide production. As nitric oxide is an important vasodilator, L-arginine supplementation would increase blood perfusion and, subsequently, muscle performance during exercises. The aim of this study was to determine the acute effect of L-arginine supplementation on strength performance and nitric oxide levels in healthy trained individuals. METHODS: In a double-blind, placebo-controlled, cross-over study, 12 men were randomly assigned to L-arginine or placebo supplementation. Subjects received 6 g of L-arginine or placebo 60 minutes before strength test (maximum number of repetitions, 3 sets at 70% of one repetition maximum on bench press and at 80% of one repetition maximum on knee extensions, 2 minutes of rest between sets and exercises). Blood samples were collected before supplementation and 6 min after exercise. RESULTS: Plasma nitrite levels did not significantly change after L-arginine or placebo supplementation and strength-training exercise (placebo, from 13.01±1.18 to 11.83±2.81 mM; L-arginine, from 10.95±4.09 to 11.99±2.5 mM). There was a significant reduction in the number of repetitions performed from set 1 to set 3 in each set of both bench press and knee extension, but no significant interactions were observed between placebo and L-arginine. CONCLUSIONS: These results do not support the use of L-arginine as an ergogenic aid for strength performance, at least in context of acute use immediately before resistance exercise performance.

Effects of Short-Term Carbohydrate Restrictive and Conventional Hypoenergetic Diets and Resistance Training on Strength Gains and Muscle Thickness.

Hypoenergetic diets and resistance training (RT) have been suggested to be important components of weight loss strategy programs; however, there is little evidence as to the chronic effects of different macronutrient compositions on strength performance and muscle mass with RT. The purpose of this study was to compare the effects of carbohydrate restrictive (CRD) and conventional (CONV) diets combined with RT on strength performance and muscle thicknesses in overweight and obese participants already involved in RT programs. Twenty-one volunteers engaged in an eight-week progressive RT program three times per week were assigned to a CRD (< 30 g carbohydrate; n = 12; 30.7 ± 3.9 km·m-2) or a CONV (30% energy deficit; 55%, 15% and 30% energy from carbohydrate, protein and fat, respectively; n=9; 27.7±2.5 km·m-2). METHOD: At baseline and week 8, the participants underwent body composition assessment by anthropometry, measurement of muscle thickness by ultrasound, and three strength tests using isotonic equipment. Both groups had similar reductions in body mass and fat mass as well as maintenance of fat-free mass. Muscle strength increased 14 ± 6% in the CRD group (p = 0.005) and 19 ± 9% in the CONV group (p = 0.028), with no significant differences between the groups. No significant differences were detected in muscle thicknesses within or between the groups. In conclusion, hypoenergetic diets combined with RT led to significant increases in muscle strength and were capable of maintaining muscle thicknesses in the upper and lower limbs of overweight and obese participants, regardless of the carbohydrate content of the diets.

Combined effects of resistance training and carbohydrate-restrictive or conventional diets on weight loss, blood variables and endothelium function / Efeitos combinados do treinamento contrarresistência e dietas restritivas em carboidrato ou convencional na perda de peso, variáveis sanguíneas e função endotelial

ABSTRACT Objective: To compare the effects of either a carbohydrate-restrictive diets or a conventional hypoenergetic diet combined with resistance training. Methods: Twenty-one overweight and obese adults participated in an eight-week program consisting of progressive resistance training combined with carbohydrate-restrictive diets (initially set at <30 g carbohydrate; n=12) or conventional hypoenergetic diet (30% energetic restriction; carbohydrate/protein/lipid: 51/18/31% of total energy consumption; n=9). It was hypothesized that the carbohydrate-restrictive diets would induce greater weight loss but that both diets would elicit similar effects on selected health markers. Body mass, and body composition, blood variables and flow-mediated brachial artery dilation (flow-mediated brachial artery dilation; by ultrasound) were used to assess changes due to the interventions. Results: Significant within-group reductions in body mass (-5.4±3.5%; p=0.001 versus -3.7±3.0%; p=0.015) and body fat (body fat; -10.2±7.0%; p=0.005 versus -9.6±8.8%; p=0.017) were identified for carbohydrate-restrictive diets and conventional hypoenergetic diet, respectively, but there were no significant differences between groups as the result of the interventions. Fat free mass, blood variables and flow-mediated brachial artery dilation did not significantly change, except for the total cholesterol/high-density lipoprotein ratio, which was reduced 10.4±16.9% in carbohydrate-restrictive diets (p=0.037) and 0.5±11.3% in conventional hypoenergetic diet (p=0.398). Conclusion: Carbohydrate-restrictive diets associated with resistance training was as effective as conventional hypoenergetic diet in decreasing body mass and body fat, as well as maintaining fat free mass, blood variables and flow-mediated brachial artery dilation, however it was more effective at lowering the total cholesterol/low density lipoprotein ratio.

RESUMO Objetivo: Comparar os efeitos entre a dieta com restrição de carboidratos e a dieta hipoenergética convencional combinadas com treinamento contrarresistência. Trabalhou-se com a hipótese de que as dietas com restrição em carboidratos poderiam acarretar maior perda de peso, mas que, no entanto, ambas causariam efeitos similares nos biomarcadores de saúde. Métodos: Vinte e um adultos com sobrepeso ou obesos participaram de um programa de 8 semanas de treinamento contrarresistência progressive combinado com dieta com restrição de carboidratos (inicialmente com <30 g de carboidrato; n=12) ou com dieta hipoenergética convencional (30% de restrição energética; carboidrato/proteína/lipídeos: 51/18/31% do valor energético total; n=9). Massa e composição corporais, variáveis sanguíneas (glicose, ureia, creatinina, ácido úrico, lipemia sanguínea, proteína creativa de alta sensibilidade) e dilatação fluxo-mediada da artéria braquial (por ultrassom) foram acompanhadas para observar os efeitos das intervenções. Resultados: Foram identificadas reduções significativas na massa corporal (-5,4±3,5%; p=0,001 versus -3,7±3,0%; p=0,015) e na gordura corporal (-10,2±7,0%; p=0,005 versus -9,6±8,8%; p=0,017) de indivíduos em dieta com restrição de carboidratos e dieta hipoenergética convencional, respectivamente, sem diferenças significativas entre os grupos. Massa livre de gordura, variáveis sanguíneas e dilatação fluxo-mediada da artéria braquial não sofreram modificações significativas, exceto a razão colesterol total/lipoproteína de alta densidade, que reduziu 10,4±16,9% em dietas com restrição de carboidratos (p=0,037) e 0,5±11,3% em dieta hipoenergética convencional (p=0,398). Conclusão: A dieta com restrição de carboidratos associada ao treinamento contrarresistência foi tão efetiva quanto a dieta convencional em reduzir a massa e a gordura corporais, assim como em manter os valores da massa livre de gordura, das variáveis sanguíneas e da dilatação fluxo-mediada da artéria braquial. No entanto, foi mais efetiva na redução da razão colesterol total/lipoproteína de baixa densidade.

Gestão da Assistência Farmacêutica: implantação de controle, rastreabilidade e farmacoeconomia / Management of Pharmaceutical Care: implementation of control, traceability and pharmacoeconomics

A Assistência Farmacêutica ocupa papel de destaque tanto no orçamento público quanto no atendimento das necessidades dos usuários do Sistema Único de Saúde (SUS). A importância do controle de estoque e dispensação, além de promover o melhor aproveitamento dos recursos da saúde, abrangem também a rastreabilidade dos usuários, medicamentos e insumos fornecidos. Mediante o diagnóstico da necessidade da reestruturação do setor de assistência farmacêutica no município de Salto/SP, diversas modificações foram realizadas visando à melhoria no atendimento à população e otimização de recursos humanos e financeiros, como a implantação de sistema informatizado nas farmácias da rede básica (Hórus - Ministério da Saúde), capacitação de funcionários do setor, descredenciamento do Programa Dose Certa para melhor gerenciamento dos recursos, da logística de compras dos medicamentos e acompanhamento dos custos com incineração por validade vencida, quantificação das medições realizadas nos aparelhos glicosímetros dos pacientes para fornecimento de insumos, parceria com farmácias credenciadas com o Programa "Aqui Tem Farmácia Popular" para divulgação dos 12 itens gratuitos de hipertensão, diabetes e asma e direcionamento da demanda SUS e o encerramento das atividades da unidade própria da Farmácia Popular do município, com a incorporação de itens na Remume - Relação Municipal de Medicamentos.

Acute l-arginine supplementation increases muscle blood volume but not strength performance.

l-Arginine (L-arg) is an amino acid precursor to nitric oxide (NO). Dietary supplements containing L-arg have been marketed with the purpose of increasing vasodilation, thereby elevating blood flow to the exercising muscle and enhancing the metabolic response to exercise. Our goal was to identify the acute effect of L-arg supplementation on biceps strength performance, indicators of NO production (nitrite and nitrate - NOx), and muscle blood volume (Mbv) and oxygenation (Mox) during recovery from 3 sets of resistance exercise. Fifteen males participated in a randomized, double-blind, placebo-controlled study. After withdrawing resting blood samples, the subjects were supplemented with 6 g of L-arg (ARG) or placebo (PLA). Monitoring of Mbv and Mox with near-infrared spectroscopy began 30 min after supplementation and lasted for 60 min. The exercise protocol (3 sets of 10 maximal voluntary contractions of isokinetic concentric elbow extension at 60°·s(-1), 2-min rest between sets) was initiated 80 min after supplementation. Blood samples were drawn at 30, 60, 90, and 120 min after supplementation. Repeated measures ANOVA showed that Mbv significantly (p ≤ 0.05) increased in ARG compared with the PLA during the recovery period of each set of resistance exercise. NOx, Mox, peak torque, total work, and set total work were not significantly different between groups. We found that acute L-arg supplementation increases Mbv during recovery from sets of resistance exercise with no increase in strength performance. It is still premature to recommend nutritional supplements containing L-arg as an ergogenic aid to increase muscle strength during resistance training in healthy subjects.

L-Arginine as a potential ergogenic aid in healthy subjects.

Dietary supplements containing L-arginine, a semi-essential amino acid, are one of the latest ergogenic aids intended to enhance strength, power and muscle recovery associated with both aerobic and resistance exercise. L-arginine is claimed to promote vasodilation by increasing nitric oxide (NO) production in the active muscle during exercise, improving strength, power and muscular recovery through increased substrate utilization and metabolite removal, such as lactate and ammonia. Research on L-arginine has recently tested this hypothesis, under the assumption that it may be the active compound associated with the vasodilator effects of NO. There were only five acute studies retrieved from the literature that evaluated exercise performance after L-arginine supplementation, three of which reported significant improvements. Regarding studies on chronic effects, eight studies were encountered: four reported enhancements in exercise performance, whilst four reports showed no changes. Whether these improvements in exercise performance - regardless of the aerobic or anaerobic nature of the exercise - can be associated with increases in NO production, has yet to be demonstrated in future studies. Low oral doses (≤20 g) are well tolerated and clinical side effects are rare in healthy subjects. In summary, it is still premature to recommend dietary supplements containing L-arginine as an ergogenic aid for healthy physically active subjects.

[Dysmenorrhea in adolescents and young adults: prevalence, related factors and limitations in daily living]. / Dismenorreia em adolescentes e jovens adultas: prevalência, factores associados e limitações na vida diária.

OBJECTIVE: To determine the prevalence of dysmenorrhea, limitations in daily living and health care use due to menstrual pain. MATERIAL AND METHODS: Observational transversal study of 274 adolescents and young adults (age ≤ 26) who had menstruated in the six months prior to the study, assisted at a Primary Health Care Center. Data were obtained by a 24-item anonymous questionnaire, which included questions about socio-demographic variables, menstrual cycle, presence, duration, severity, treatment and limitations of dysmenorrhea. RESULTS: One hundred and seventy-two (62.8%) subjects experienced menstrual pain. Of these, 65.7% reported having limitations in their daily activities due to dysmenorrhea. The prevalence of limitations in daily living was influenced by the presence of additional symptoms (r=0.331; p <0.001), pain intensity (r=0.281; p <0.001) and pain duration (r=0.172; p=0.027). The most commonly mentioned limitation was anxiety/depression (42.5%). Fourteen of the subjects reported missing school or work due to dysmenorrhea. A total of 48 respondents sought medical help and 135 reported using therapeutic measures to ease their pain. The most common treatments reported for pain treatment included NSAID's (38.5%) and oral pills (37.0%). The existence of additional symptoms (r=0.247; p=0.001) and the intensity of pain (r=0.160; p=0.039) led to the search for health care. CONCLUSIONS: Dysmenorrhea is highly prevalent among this sample of adolescents and young adults and is related to absenteeism. Thus, health care providers should regularly screen for dysmenorrhea and offer appropriate treatment.

Confiabilidade da medida de espessuras musculares pela ultrassonografia / Reliability of muscle thickness measurements using ultrasound

OBJETIVO: Determinar a confiabilidade das medidas de espessuras dos músculos flexores e extensores do cotovelo e joelho pela ultrassonografia (US), quantificando o erro típico associado a essas medidas (ETM). MÉTODOS: A confiabilidade (duas medidas interdias) foi determinada em 15 voluntários aparentemente saudáveis (oito mulheres, 33,9 ± 11,4 anos, 76 ± 21kg, 170 ± 10cm). As imagens da musculatura flexora (FC) e extensora do cotovelo (EC) e flexora (FJ) e extensora do joelho (EJ) foram obtidas pela US bidimensional no modo B, utilizando transdutor de 7,5MHz. As espessuras do tecido muscular compreendidas entre as interfaces com o osso e com o tecido adiposo foram medidas em sítios anatômicos identificados e registrados para ser repetidos na segunda medida. RESULTADOS: A ANOVA não identificou diferenças significativas entre as medidas repetidas. Os coeficientes de correlação intraclasse foram FC = 0,970, EC = 0,971, FJ = 0,555 e EJ = 0,929 (P < 0,05 para todos). Os coeficientes de variação foram de 3,9 por cento, 6,1 por cento, 6,6 por cento e 4,6 por cento, e os ETM 1,3mm, 1,6mm, 4,9mm e 1,9mm, respectivamente, para espessuras de FC, EC, FJ e EJ. A análise dos gráficos de Bland-Altman apontou que as variáveis não apresentaram erro heterocedástico. CONCLUSÃO: As medidas de espessuras musculares de FC, EC e EJ apresentaram alta confiabilidade, possibilitando seu uso para intervenções como programas de dieta, treinamento físico ou reabilitação. No entanto, o uso da medida de FJ não deve ser recomendada, pois mostrou baixa confiabilidade e alto ETM.

PURPOSE: To determine the reliability of muscle thickness measurements of elbow and knee flexors and extensors using ultrasound, and to quantify the typical error associated to the measurements (TEM). METHODS: The test-retest reliability was determined in 15 apparently healthy volunteers (8 women, 34 ± 11 years, 76 ± 21 kg, 170 ± 10 cm). The images of elbow flexors (EF) and extensors (EE) and knee flexors (KF) and extensors (KE) were obtained using a two dimensional mode B ultrasound instrument with a 7.5 MHz transducer. Muscle thickness between the adipose tissue and bone interfaces were measured at anatomical landmarks previously identified and recorded to assure the exact site for the retest. RESULTS: ANOVA did not identify any significant differences between the repeated measurements. Intraclass correlation coefficients (ICC) of each pair of measure were EF = 0.970, EE = 0.971, KF = 0.555 e KE = 0.929 (P < 0.05 for all). The coefficients of variation were 3.9 percent, 6.1 percent, 6.6 percent e 4.6 percent, and TEM 1.3 mm, 1.6 mm, 4.9 mm e 1.9 mm, respectively, for the EF, EE, KF and KE thickness. Analysis of the Bland-Altman plot charts indicated that the variables did not present heterocedastic errors. CONCLUSION: EF, EE and KE muscle thickness measurements using the current method were highly reliable and can be used to measure and monitor changes in diet, physical training and rehabilitation programs. Nevertheless, KF measure should not be recommended since it presented low reliability and high TEM.

Efeitos da suplementação de beta-hidroxi-beta-metilbutirato sobre a força e a hipertrofia: [revisão] / Effects of beta-hydroxy-beta-methylbutyrate supplementation on strength and hypertrophy: [review]

O beta-hidroxi-beta-metilbutirato é um metabólito da leucina estudado devido aos seus efeitos anticatabólicos e possíveis implicações sobre os ganhos de força e massa muscular associados ao treinamento contra-resistência (conhecido como musculação). O objetivo deste trabalho foi revisar a literatura referente à suplementação de beta-hidroxi-beta-metilbutirato e os seus efeitos sobre força e hipertrofia em adultos jovens e idosos iniciantes ou treinados em treinamento contra-resistência. Estudos em indivíduos iniciando um programa de treinamento contra-resistência sugerem que a suplementação diária de 1,5 a 3,0g de beta-hidroxi-beta-metilbutirato pode trazer benefício ergogênico durante as primeiras quatro ou cinco semanas. Entretanto, à medida que o programa de treinamento evolui, tais efeitos não permanecem e os ganhos de força e massa muscular são proporcionados apenas pelo treinamento contra-resistência. Em indivíduos treinados, os resultados parecem não ser os mesmos, uma vez que, desde o início da suplementação, o beta-hidroxi-beta-metilbutirato não demonstra qualquer benefício adicional aos induzidos pelo treinamento contra-resistência. Alguns efeitos do beta-hidroxi-beta-metilbutirato na redução do colesterol total e lipoproteína de baixa densidade também foram observados, porém, devido às poucas evidências, não há recomendações para tal finalidade. Nenhum efeito adverso da suplementação foi observado, sendo, aparentemente, segura, contudo a maioria dos estudos foi realizada em curto prazo (menos de 4 semanas) e em indivíduos destreinados. Assim, mais estudos são necessários para esclarecer o mecanismo fisiológico por meio do qual o beta-hidroxi-beta-metilbutirato exerce seus efeitos anticatabólicos em destreinados e para observar possíveis efeitos adversos.

Beta-hydroxy-beta-methylbutyrate is a leucine metabolite studied for its anticatabolic effects and potential benefits on strength and muscle mass gains associated with resistance training. The aim of this review was to discuss the effects of beta-hydroxy-beta-methylbutyrate supplementation on strength and hypertrophy in previously trained or untrained young and older adults. Studies undertaken with individuals initiating a resistance training program have suggested that a daily beta-hydroxy-beta-methylbutyrate supplementation dosage of 1.5 to 3.0g may be responsive as an ergogenic aid up to the fourth or fifth week of resistance training. Such effects do not seem to remain afterward, when gains in strength and muscle mass are the result of resistance training only. In resistance trained subjects beta-hydroxy-beta-methylbutyrate supplementation did not show any additional benefits during resistance training. Beta-hydroxy-beta-methylbutyrate supplementation has been shown to reduce total cholesterol and low-density lipoprotein cholesterol, although there seems to be no available recommendation for its supplementation, since scientific evidence is lacking. No beta-hydroxy-beta-methylbutyrate adverse effects have been observed, and its supplementation is apparently safe, however, most studies were conducted during a short-term period (less then 4 weeks) and with untrained individuals. There is a need for more studies to elucidate the physiological mechanisms underlying the anticatabolic action of beta-hydroxy-beta-methylbutyrate supplementation in untrained subjects, and to investigate possible adverse effects.

Reliability of brachial artery flow-mediated dilatation measurement using ultrasound.

OBJECTIVE: To determine the reliability of the baseline (BBAB) and post occlusion (POBAD) brachial artery diameters, brachial artery flow-mediated dilatations (BAFMD) measurements, and to quantify the typical error of the measurements (TEM). METHODS: Internal consistency (2 measurements on the same day) was determined in 10 volunteers, whereas stability (2 measurements on separate days) was determined in 13 volunteers. All the volunteers looked healthy and were nonsmokers. The brachial artery images were obtained using a two dimensional Doppler ultrasound instrument: a 14 MHz transducer was used. The distances between the intima-lumen interfaces were measured before and after the blood flow had been stopped by means of a cuff on the arm for five minutes. BAFMD was considered as the percentile increase of POBAD in relation to BBAD. RESULTS: ANOVA did not identify any significant differences between the measurements taken on the same and separate days. For BAFMD, the intraclass correlation coefficients between the measurements taken on the same and separate days were: R = 0.7001 and R = 0.8420, respectively (p < 0.05). The variation coefficients were 5.8% and 12.4% and the relative SMEs were 13.8% and 14.9%, respectively, for the measurements taken on the same and separate days. Analysis of the Bland-Altman graphs indicated that the variables did not present heteroscedastic errors. CONCLUSION: The BBAD, POBAD and BAFMD measurements using the manual ultrasound technique were highly reliable for both the same and separate day measurements and therefore can be used to diagnose and monitor endothelial function.

Confiabilidade da medida da dilatação fluxo-mediada da artéria braquial pela ultra-sonografia / Reliability of brachial artery flow-mediated dilatation measurement using ultrasound

OBJETIVO: Determinar a confiabilidade das medidas dos diâmetros basal (DBAB) e pós-oclusão (DPOAB) da artéria braquial e da dilatação fluxo-mediada da artéria braquial (DILA), assim como quantificar o erro típico dessas medidas (ETM). MÉTODOS: A consistência interna (2 medidas intradias) foi determinada em 10 voluntários, enquanto a estabilidade (2 medidas interdias) foi determinada em 13 voluntários aparentemente saudáveis e não-fumantes. As imagens da artéria braquial foram obtidas pelo aparelho de ultra-sonografia bidimensional com Doppler, utilizando transdutor de 14 MHz. As distâncias entre as interfaces íntima-luz foram medidas antes e após interrupção do fluxo sangüíneo durante 5 minutos por manguito posicionado no braço. O DILA foi considerado o porcentual de aumento do DPOAB em relação ao DBAB. RESULTADOS: A ANOVA não identificou diferenças significativas entre as medidas intradias e interdias. Para o DILA, os coeficientes de correlação intraclasse entre as medidas intradias e interdias foram R = 0,7001 e R = 0,8420, respectivamente (p < 0,05). Os coeficientes de variação foram 5,8 por cento e 12,4 por cento e os ETM relativos 13,8 por cento e 14,9 por cento, respectivamente para medidas intra e interdias. A análise dos gráficos de Bland-Altman apontou que as variáveis não apresentaram erro heterocedástico. CONCLUSÃO: A medida do DBAB, DPOAB e do DILA por meio de técnica manual pela ultra-sonografia apresenta alta confiabilidade tanto para os valores intradias quanto interdias, possibilitando seu uso para diagnóstico e monitoramento da função endotelial.

OBJECTIVE: To determine the reliability of the baseline (BBAB) and post occlusion (POBAD) brachial artery diameters, brachial artery flow-mediated dilatations (BAFMD) measurements, and to quantify the typical error of the measurements (TEM). METHODS: Internal consistency (2 measurements on the same day) was determined in 10 volunteers, whereas stability (2 measurements on separate days) was determined in 13 volunteers. All the volunteers looked healthy and were nonsmokers. The brachial artery images were obtained using a two dimensional Doppler ultrasound instrument: a 14 MHz transducer was used. The distances between the intima-lumen interfaces were measured before and after the blood flow had been stopped by means of a cuff on the arm for five minutes. BAFMD was considered as the percentile increase of POBAD in relation to BBAD. RESULTS: ANOVA did not identify any significant differences between the measurements taken on the same and separate days. For BAFMD, the intraclass correlation coefficients between the measurements taken on the same and separate days were: R = 0.7001 and R = 0.8420, respectively (p < 0.05). The variation coefficients were 5.8 percent and 12.4 percent and the relative SMEs were 13.8 percent and 14.9 percent, respectively, for the measurements taken on the same and separate days. Analysis of the Bland-Altman graphs indicated that the variables did not present heteroscedastic errors. CONCLUSION: The BBAD, POBAD and BAFMD measurements using the manual ultrasound technique were highly reliable for both the same and separate day measurements and therefore can be used to diagnose and monitor endothelial function.

Gasto energético e consumo de oxigênio pós-exercício contra-resistência / Energy expenditure and excess post-exercise oxygen consumption of resistance exercise

O aumento do gasto energético com a atividade física é reconhecido como um importante coadjuvante em programas para redução da massa corporal. Porém, o impacto do exercício contra-resistência, incluindo o consumo de oxigênio em excesso pós-exercício sobre o gasto energético ainda é questionável. O objetivo desta revisão foi discutir a influência das variáveis do exercício contra-resistência (isto é, intensidade, intervalo de recuperação, velocidade de execução, número de séries, e modo - circuito ou contínuo) sobre o gasto energético durante e após uma sessão de exercícios, envolvendo uma discussão sobre os possíveis mecanismos do consumo de oxigênio em excesso pós-exercício. As inúmeras possibilidades de combinação entre tais variáveis podem favorecer uma variabilidade bastante grande no gasto energético de uma sessão de exercício contra-resistência (aproximadamente de 3 a 10kcal.min-1). Contudo, o volume total de trabalho parece ser determinante no gasto energético da sessão. O consumo de oxigênio em excesso pós-exercício, por outro lado, parece ser afetado pela intensidade. A manipulação das variáveis do exercício contra-resistência pode afetar os processos metabólicos subjacentes ao consumo de oxigênio em excesso pós-exercício, o que inclui ressíntese dos estoques de fosfato de alta energia, ressaturação da oximioglobina e oxihemoglobina, efeitos termogênicos, remoção de lactato, aumento no turnover protéico, e processos desencadeados pela estimulação simpática. Conclui-se que, para indivíduos destreinados e com sobrepeso, a prescrição de escolha poderia ser a de sessões de baixa intensidade e alto volume. Contudo, para indivíduos treinados, o aumento do gasto energético, a partir da execução de sessões de exercício contra-resistência mais intensas, pode ser adequado, dada a influência da intensidade sobre o consumo de oxigênio em excesso pós-exercício. Dessa forma, para a prescrição dietética, o nutricionista deve considerar e se ...

The increase in energy expenditure through physical activity is recognized as an important component in weight loss programs. The impact of resistance exercise, including excess post-exercise oxygen consumption (correspond to the post-exercise energy expenditure), on energy expenditure, however, remains inconclusive. The purpose of the present review was to discuss the influence of the resistance exercise variables (intensity, rest interval, movement velocity, number of sets, and type - circuit or continuous) on energy expenditure during and after an exercise bout. The excess post-exercise oxygen consumption mechanisms were also discussed. The innumerous possibilities of combinations among resistance exercise variables result in a wide range of energy expenditure values for an exercise session (approximately between 3 to 10kcal·min-1). Nevertheless, volume appears to be determinant in the energy expenditure of resistance exercise itself, excess post-exercise oxygen consumption, on the other side, may be affected by exercise intensity. The manipulation of resistance exercise variables may affect the metabolic processes underlying excess post-exercise oxygen consumption, including resynthesis of high energy phosphates stores, resaturation of oxyhemoglobin and oxymyoglobin, thermogenic effects, lactate removal, increased protein turnover, and effects mediated by sympathetic activity. In conclusion, it might be advisable to use low intensity and high volume exercises in a training session for untrained and overweight subjects. However, trained individuals could benefit from more intense resistance exercise, due to the effects of intensity on excess post-exercise oxygen consumption. Thus, nutritionists should consider the effects of resistance exercise on total energy expenditure in order to prescribe effective diets for weight loss purposes.

Efeitos agudos da atividade contra-resistência sobre o gasto energético: revisitando o impacto das principais variáveis / Acute effects of resistance exercise on energy expenditure: revisiting the impact of the training variables

Considerando a crescente prevalência de sobrepeso e obesidade no Brasil e em várias partes do mundo, tornam-se necessárias estratégias que busquem o seu controle. A associação entre dieta e exercícios físicos aeróbios é, há muito, reconhecida como uma maneira inócua e efetiva de contornar o problema; já o impacto da atividade contra-resistência na perda de peso é, ainda, bastante questionável. Assim, o objetivo da presente revisão foi discutir o efeito termogênico da atividade contra-resistência, buscando esclarecer o impacto das diversas variáveis - intensidade, duração, número de séries, intervalo entre séries, velocidade de execução e modo (circuito ou séries múltiplas) a ela relacionadas. Os estudos apontam que a atividade contra-resistência pode aumentar o gasto energético total de forma aguda, através do próprio custo energético de sua execução, assim como durante o período de recuperação (EPOC). É reconhecido, também, que as diversas variáveis associadas ao exercício contra-resistência afetam de maneiras distintas os resultados obtidos. Número de repetições, carga, intervalo de recuperação entre séries e número de séries, quando manipulados de forma a aumentar o volume ou a intensidade da atividade, podem, em última análise, aumentar sobremaneira o gasto energético decorrente de uma sessão típica de exercícios. De maneira geral, considerando todas as limitações dos estudos revisados, a literatura aponta que o volume é a variável de maior impacto sobre o gasto energético durante a realização da atividade e a intensidade sobre o EPOC.

Nutrição e exercício na prevenção e controle das doenças cardiovasculares / Nutrition and exercise on cardiovascular disease prevention and control

As doenças cardiovasculares constituem a principal causa de mortalidade no mundo e o seu crescimento significativo nos países em desenvolvimento alerta para o potencial impacto nas classes menos favorecidas. São influenciadas por um conjunto de fatores de risco, alguns modificáveis mediante alterações no estilo de vida, como a dieta adequada e o exercício regular. O objetivo da presente revisão é abordar esses aspectos a fim de prevenir e controlar as doenças cardiovasculares. O consumo de vegetais, frutas, grãos integrais, soja, azeite e peixes deve ser aumentado, ainda que limitando a quantidade de gordura. Os alimentos ricos em ácidos graxos saturados e trans devem ser evitados, assim como o uso excessivo de sal e bebidas alcoólicas. Além do exercício aeróbio, as atividades contra resistência vêm aumentando sua importância na reabilitação cardíaca. Essas mudanças de estilo de vida deveriam ser prioridades na Saúde Pública a fim de deter o avanço das doenças cardiovasculares em nosso país.

Dietas vegetarianas: caracterização, implicações nutricionais e controvérsias / Vegetarian diets: characterization, nutritional implications, and controversies

A literatura é divergente quanto às repercussões da dieta vegetariana sobre a saúde. Várias pesquisas apontam seus efeitos positivos, enquanto outros ressaltam seus aspectos prejudiciais. Quanto aos benefícios, salienta-se a menor prevalência de enfermidades não transmissíveis em vegetarianos e, em contrapartida, são abordados os riscos de surgimento de estados carenciais entre seus adeptos, principalmente durante fases de maior vulnerabilidade biológica. Portanto, o objetivo do presente estudo foi relacionar os avanços dos conhecimentos científicos sobre o tema, principalmente no que diz respeito às implicações nutricionais sobre o estado nutricional de indivíduos durante o crescimento