Creatine supplementation: ergogenic and therapeutic effects

A creatina foi descoberta há mais de um século, porém seu uso tornou-se importanteno cenário esportivo a partir dos anos 70. Desde então, o aprofundamento dos conhecimentose dos protocolos de utilização fez desta substância o recurso ergogênico lícito mais estudado eutilizado por atletas atualmente. Os benefícios da suplementação em atletas serviram de modelopara estudo da utilização como adjuvante terapêutico em indivíduos doentes, que apresentamalguma deficiência de síntese e ressíntese de ATP, doenças neurológicas e musculares, ouque cursam com atrofia ou prejuízo do metabolismo muscularCreatine was discovered more than one century ago, but its use became importantin sports scenario in the 70’s. Since then, the improvement in knowledge and utilization protocolsmade this substance the licit ergogenic aid most studied and used by athletes nowadays. Thebenefits of supplementation in athletes served as a model for studies in diseased individuals,that present ATP synthesis or ressynthesis deficiency, neurological and muscular diseases,or that suffer from muscular atrophy or impairment of muscular metabolis

Strength training benefits on the physical fitness of elderly individuals

O objetivo desta revisão é elucidar os benefícios do treinamento com pesos (TP) sobre quatro componentes da aptidão física (AF) fundamentais para a qualidade de vida de idosos: força, flexibilidade, equilíbrio e resistência aeróbia. Foi realizada pesquisa bibliográfica nas bases de dados PUBMED e LILACS. Foram selecionados estudos que incluíam no título os descritores: strength training, resistance training, strength, balance, flexibility, power, aerobic, older e elderly. Modificações na força muscular são observadas após poucas semanas de TP. Essa melhoria pode auxiliar não só na independência dos idosos, mas também na diminuição da incidência de quedas. Além disso, a prática sistematizada do TP promove melhoria na flexibilidade e na resistência aeróbia de idosos. As modificações no equilíbrio, após programas de TP, ainda não estão bem esclarecidas na literatura. Desta forma, o TP consiste numa importante ferramenta para a melhoria da AF de idosos, haja vista que promove adaptações na força muscular, flexibilidade e na resistência aeróbia.The objective of this review is to assess the benefits of strength training (ST) over four very important components of physical fitness (PF) of the elderly: strength, flexibility, balance and aerobic resistance. A literature search was carried out through PUBMED and LILACS. Articles which included the following words in their titles were selected: strength training, resistance training, strength, balance, flexibility, power, aerobic, older, and elderly. Strength modifications can be observed after a few weeks of ST. This improvement can help the elderly not only by providing independence, but also by reducing the incidence of falls. Moreover, the systematic practice of ST by the elderly promotes better flexibility and aerobic resistance. Balance modifications after ST programs have not been well established in the literature. Thus, ST is an important resource for the improvement of PF in the elderly, as it promotes adaptations in muscular strength, flexibility and aerobic resistance

Intensidade de Exercício durante o Teste de Caminhada de 6 Minutos em Pacientes com Doença Arterial Periférica. = Exercise intensity during 6-minute walk test in patients with peripheral artery disease.

Fundamento: a caminhada não supervisionada em solo tem sido indicada para pacientes com doença arterial periférica (DAP) sintomática. No entanto, a magnitude do esforço exigido por essa atividade e as características dos pacientes que a praticam com mais intensidade não estão claras. Objetivos: determinar se a caminhada em solo excede o limiar ventilatório (LV), um reconhecido marcador de intensidade de exercício, em pacientes com DAP sintomática. Métodos: Foram recrutados 70 pacientes (61,4% do sexo masculino e com idade entre 40 e 85 anos) com DAP sintomática. Os pacientes realizaram um teste ergométrico em esteira para definir o LV. Em seguida, foram submetidos ao teste de caminhada de 6 minutos para determinar o alcance do LV durante deambulação no solo. Realizou-se regressão logística múltipla para identificar preditores de LV durante o teste de caminhada de 6 minutos, e o valor de p<0,05 foi considerado significativo para todas as análises. Resultados: Ao todo, 60% dos pacientes atingiram o LV durante o teste de caminhada de 6 minutos. Mulheres (OR = 0,18 e IC95% = 0,05 a 0,64) e pacientes com mais aptidão cardiorrespiratória (OR = 0,56 e IC 95% = 0,40 a 0,77) tiveram menor probabilidade de chegar ao LV durante a caminhada em solo em comparação a homens e pacientes com menos aptidão cardiorrespiratória, respectivamente. Conclusão: Mais da metade dos pacientes com DAP sintomática alcançou o LV durante o teste de caminhada de 6 minutos. Mulheres e pacientes com mais aptidão cardiorrespiratória têm menos probabilidade de chegar ao LV durante o teste de caminhada de 6 minutos, o que indica que a caminhada no solo pode ser mais intensa para esse grupo. Isso deve ser considerado ao se prescreverem exercícios de caminhada em solo para esses pacientes. (Arq Bras Cardiol. 2020; 114(3):486-492) = Background: Non-supervised ground walking has been recommended for patients with symptomatic peripheral artery disease (PAD). However, the magnitude of the effort required by this activity and the characteristics of patients whose ground walking is more intense are unclear. Objectives: To determine whether ground walking exceeds the ventilatory threshold (VT), a recognized marker of exercise intensity, in patients with symptomatic PAD. Methods: Seventy patients (61.4% male and aged 40 to 85 years old) with symptomatic PAD were recruited. Patients performed a graded treadmill test for VT determination. Then, they were submitted to a 6-minute walk test so the achievement of VT during ground ambulation could be identified. Multiple logistic regression was conducted to identify predictors of VT achievement during the 6-minute walk test. The significance level was set at p < 0.05 for all analyses. Results: Sixty percent of patients achieved VT during the 6-minute walk test. Women (OR = 0.18 and 95%CI = 0.05 to 0.64) and patients with higher cardiorespiratory fitness (OR = 0.56 and 95%CI = 0.40 to 0.77) were less likely to achieve VT during ground walking compared to men and patients with lower cardiorespiratory fitness, respectively. Conclusion: More than half of patients with symptomatic PAD achieved VT during the 6-minute walk test. Women and patients with higher cardiorespiratory fitness are less likely to achieve VT during the 6-minute walk test, which indicates that ground walking may be more intense for this group. This should be considered when prescribing ground walking exercise for these patients. (Arq Bras Cardiol. 2020; 114(3):486-492)

Physical Activity Levels in Peripheral Artery Disease Patients

BACKGROUND: Increases in daily physical activity levels is recommended for patients with peripheral artery disease (PAD). However, despite this recommendation, little is known about the physical activity patterns of PAD patients. OBJECTIVE: To describe the physical activity patterns of patients with symptomatic peripheral artery (PAD) disease. METHODS: This cross-sectional study included 174 PAD patients with intermittent claudication symptoms. Patients were submitted to clinical, hemodynamic and functional evaluations. Physical activity was objectively measured by an accelerometer, and the time spent in sedentary, low-light, high-light and moderate-vigorous physical activities (MVPA) were obtained. Descriptive analysis was performed to summarize patient data and binary logistic regression was used to test the crude and adjusted associations between adherence to physical activity recommendation and sociodemographic and clinical factors. For all the statistical analyses, significance was accepted at p < 0.05. RESULTS: Patients spent in average of 640 ± 121 min/day, 269 ± 94 min/day, 36 ± 27 min/day and 15 ± 16 min/day in sedentary, low-light, high-light and MVPA, respectively. The prevalence of patients who achieved physical activity recommendations was 3.4%. After adjustment for confounders, a significant inverse association was observed between adherence to physical activity recommendation and age (OR = 0.925; p = 0.004), while time of disease, ankle brachial index and total walking distance were not associated with this adherence criteria (p > 0.05). CONCLUSION: The patterns of physical activity of PAD patients are characterized by a large amount of time spent in sedentary behaviors and a low engagement in MVPA. Younger patients, regardless of the clinical and functional factors, were more likely to meet the current physical activity recommendations

Post‐resistance exercise hypotension in patients with intermittent claudication

OBJECTIVE: To verify the acute effects of resistance exercise on post-exercise blood pressure in patients with intermittent claudication. METHODS: Eight patients randomly underwent two experimental sessions: a session of resistance exercise (R: 6 exercises, 3 sets of 12, 10 and 8 reps with a perceived exertion of 11 to 13 on the 15-grade Borg scale) and a control session (C: resting on exercise machines). RESULTS: Before and for 60 min following an intervention, auscultatory blood pressure was measured while subjects rested in a sitting position. After the C session, systolic, diastolic and mean blood pressures did not change from the pre-intervention values, while these values decreased significantly after the R session throughout the entire recovery period (greatest decreases = -14 ± 5, -6±5, and -9 ± 4 mmHg, respectively, P < 0.05). CONCLUSION: After a single bout of resistance exercise patients with intermittent claudication exhibited reduced systolic, diastolic and mean blood pressures, suggesting that acute resistance exercise may decrease cardiovascular load in these patients

Stages of health behavior change and factors associated with physical activity in patients with intermittent claudication

OBJECTIVE: To analyze, in people with intermittent claudication, the frequency of individuals who are in each of stages of health behavior change to practice physical activity, and analyze the association of these stages with the walking capacity. METHODS: We recruited 150 patients with intermittent claudication treated at a tertiary center, being included those > 30-year-old-individuals and who had ankle-arm index < 0.90. We obtained socio-demographic information, presence of comorbidities and cardiovascular risk factors and stages of health behavior change to practice physical activity through a questionnaire, they being pre-contemplation, contemplation, preparation, action and maintenance. Moreover, the walking capacity was measured in a treadmill test (Gardner protocol). RESULTS: Most individuals were in the maintenance stage (42.7%), however, when the stages of health behavior change were categorized into active (action and maintenance) and inactive (pre-contemplation, contemplation and preparation), 51.3% of the individuals were classified as inactive behavior. There was no association between stages of health behavior change, sociodemographic factors and cardiovascular risk factors. However, patients with intermittent claudication who had lower total walking distance were three times more likely to have inactive behavior. CONCLUSION: Most patients with intermittent claudication showed an inactive behavior and, in this population, lower walking capacity was associated with this behavior

Health-related quality of life in Brazilian community-dwelling and institutionalized elderly: Comparison between genders

Objective: To compare the health-related quality of life (HRQL) indicators between institutionalized and community-dwelling elderly men and women. Method: This was a cross-sectional study with a sample of 496 elderly men and women, surveyed by researchers at a private hospital that attends institutionalized and community-dwelling elderly. HRQL (World Health Organization Quality of Life), daily living activities (Katz questionnaire), and instrumental daily living activities (Lawton questionnaire), mini-mental state examination, handgrip strength test, and function capacity (timed up and go test) were obtained. Results: Institutionalized men presented higher scores in physical and psychological domains of HRQL compared to elderly men living alone (p<0.05). Among women, the scores in all domains (physical, psychological, relationship, and environment) were similar between institutionalized and community-dwelling individuals. Conclusion: Institutionalized elderly men reported better scores in physical and psychological domains of HRQL compared to their community-dwelling pairs, while both institutionalized and community-dwelling elderly women presented similar HRQL

Is the algorithm used to process heart rate variability data clinically relevant? Analysis in male adolescents

OBJECTIVE: To analyze whether the algorithm used for the heart rate variability assessment (fast Fourier transform versus autoregressive methods) influenced its association with cardiovascular risk factors in male adolescents. METHODS: This cross-sectional study included 1,152 male adolescents (aged 14 to 19 years). The low frequency, high frequency components (absolute numbers and normalized units), low frequency/high frequency ratio, and total power of heart rate variability parameters were obtained using the fast Fourier transform and autoregressive methods, while the adolescents were resting in a supine position. RESULTS: All heart rate variability parameters calculated from both methods were different (p<0.05). However, a low effect size (<0.1) was found for all parameters. The intra-class correlation between methods ranged from 0.96 to 0.99, whereas the variation coefficient ranged from 7.4 to 14.8%. Furthermore, waist circumference was negatively associated with high frequency, and positively associated with low frequency and sympatovagal balance (p<0.001 for both fast Fourier transform and autoregressive methods in all associations). Systolic blood pressure was negatively associated with total power and high frequency, whereas it was positively associated with low frequency and sympatovagal balance (p<0.001 for both fast Fourier transform and autoregressive methods in all associations). Body mass index was negatively associated with high frequency, while it was positively associated with low frequency and sympatovagal balance (p values ranged from <0.001 to 0.007). CONCLUSION: There are significant differences in heart rate variability parameters obtained with the fast Fourier transform and autoregressive methods in male adolescent; however, these differences are not clinically significant. OBJETIVO: Analisar se o algoritmo usado para avaliação da variabilidade da frequência cardíaca (transformada rápida de Fourier versus autoregressivo) influencia em sua associação com fatores de risco cardiovascular adolescentes do gênero masculino. MÉTODOS: Estudo transversal, que incluiu 1.152 adolescentes do gênero masculino (14 a 19 anos). Componentes de baixa e alta frequência (absolutos e unidades normalizadas), razão componente de baixa frequência/componente de alta frequência e poder total da variabilidade da frequência cardíaca foram obtidos em repouso, na posição supina, usando os métodos transformada rápida de Fourier e autorregressivo. RESULTADOS: Todos os parâmetros da variabilidade da frequência cardíaca para ambos os métodos foram diferentes (p<0,05). Entretanto, um pequeno tamanho do efeito (<0,1) foi observado para todos os parâmetros. Os coeficientes de correlação intraclasse entre os métodos variaram de 0,96 a 0,99, enquanto os coeficientes de variação foram de 7,4 a 14,8%. A circunferência abdominal foi negativamente associada com o componente de alta frequência, e positivamente associada com o componente de baixa frequência e o balanço simpatovagal (p<0,001 para a transformada rápida de Fourier e o autorregressivo em todas as associações). A pressão arterial sistólica foi negativamente associada com o poder total e o componente de alta frequência, enquanto foi positivamente associada com o componente de baixa frequência e o balanço simpatovagal (p<0,001 para a transformada rápida de Fourier e o autorregressivo em todas as associações). O índice de massa corporal foi negativamente associado com o componente de alta frequência, enquanto foi positivamente associado com o componente de baixa frequência e o balanço simpatovagal (valores de p variando de <0,001 a 0,007). CONCLUSÃO: Houve diferenças significantes nos parâmetros da variabilidade da frequência cardíaca obtidos com os métodos transformada rápida de Fourier e autorregressivo em adolescentes masculinos, mas essas diferenças não foram clinicamente significativas

Cardiovascular responses during isokinetic muscle assessment in claudicant patients

FUNDAMENTO: A dinamometria isocinética tem tido crescente importância para avaliação da função muscular em indivíduos com claudicação intermitente. No entanto, ainda há escassez de informações sobre as respostas cardiovasculares desses doentes durante este tipo de avaliação. OBJETIVO: Avaliar e comparar as respostas cardiovasculares na avaliação da força e resistência muscular de dois exercícios comumente utilizados para de pacientes com CI (flexão plantar/dorsiflexão e flexão/extensão de joelhos). MÉTODOS: Dezessete claudicantes com doença estável há pelo menos 6 meses compuseram a amostra avaliada no dinamômetro isocinético. Frequência cardíaca, pressão arterial e duplo produto foram mensurados não invasivamente em repouso e no pico do esforço, em protocolos específicos para avaliação de força e resistência muscular. RESULTADOS: Com exceção da pressão arterial diastólica, a frequência cardíaca, pressão arterial sistólica e o duplo produto aumentaram durante o exercício em comparação ao repouso (p < 0,05). A frequência cardíaca e o duplo produto sofreram maior elevação durante o exercício de extensão/flexão de joelho, em comparação ao exercício de flexão plantar/dorsiflexão (P < 0,05). Maiores incrementos na frequência cardíaca foram observados durante o protocolo de avaliação da resistência em comparação ao da avaliação da força muscular. CONCLUSÃO: Os testes isocinéticos de avaliação da força e resistência musculares em pacientes com CI promovem aumento da frequência cardíaca, da pressão arterial sistólica e do duplo produto durante sua execução. Estes aumentos são maiores nos testes de resistência muscular e nos que envolvem maior massa muscular, sugerindo que testes de força de pequenos grupamentos musculares promovem menor sobrecarga cardiovascular nesses pacientes.BACKGROUND: Isokinetic dynamometry is becoming increasingly important for the assessment of muscle function in individuals with intermittent claudication. However, there is still little information available about the cardiovascular responses of these patients during this type of assessment. OBJECTIVE: To assess and compare the cardiovascular responses recorded during the assessment of muscle strength and endurance for two exercises commonly used in patients with IC (plantar flexion/dorsiflexion and knee flexion/extension). METHODS: The sample consisted of 17 claudicant patients with stable disease for at least 6 months. During the isokinetic dynamometer testing, non-invasive measurements of heart rate, blood pressure and double product at rest and at peak exertion were obtained according to specific protocols established for muscle strength and endurance assessment. RESULTS: Except for diastolic blood pressure, heart rate, systolic blood pressure and double product values rose during the exercise compared to the resting stage (p < 0.05). Elevations in heart rate and double product values were higher during knee extension/flexion than during plantar flexion/dorsiflexion (p < 0.05). Increases in heart rate were also higher during the endurance assessment protocol than during muscle strength assessment. CONCLUSION: Isokinetic strength and endurance testing in patients with IC results in elevation of heart rate, systolic blood pressure and double product values during the exercises. These increases are higher during the muscle endurance exercises and in those involving greater muscle mass, suggesting that strength testing of small muscle groups causes less cardiovascular overload in these patients