Variation of the muscular balance during a season in under-20 soccer players

O objetivo deste estudo foi analisar o equilíbrio muscular dos flexores e extensores (RFE) de joelho ao longo de uma temporada de treinamento em jogadores de futebol categoria sub-20. Fizeram parte da amostra 15 sujeitos pertencentes à equipe sub-20 da Associação Atlética Ponte Preta de Campinas. Os atletas participaram de um macrociclo de preparação (MP) de 29 semanas, composto por período preparatório e competitivo que foram divididos em quatro mesociclos: etapa geral (M1), etapa especial (M2), etapa pré-competitiva (M3) e etapa competitiva (M4). A RFE de ambos os membros foi determinada em dinamômetro isocinético utilizando o pico de torque (PT) obtido em três séries consecutivas de cinco repetições com velocidade de 60º/s. Avaliação isocinética foi realizada em quatro momentos ao longo do MP, sempre ao final de cada mesociclo (M1, M2, M3 e M4). Para análise estatística, foi empregado teste Friedman de medidas repetidas, seguida do teste de Wilcoxon e teste U de Mann-Whitney, com nível de significância de p<0,05. O PT nos músculos flexores de joelho, em ambos os membros, no M2 e M3 foram superiores aos observados em M1 e M4. O PT dos extensores de joelho em M1 foi significantemente inferior aos demais momentos do estudo (M2, M3 e M4), em ambos os membros. A RFE, em ambos os membros, foi inferior em M1 quando comparado a M2 e M3. A comparação da RFE entre os membros não revelou diferenças significantes em nenhum dos momentos do estudo (M1, M2, M3 e M4). Os resultados encontrados na presente investigação indicaram existência de alterações na magnitude da RFE, porém dentro da normalidade, e, manutenção da proporcionalidade entre os membros ao longo do MP. Esses resultados sugerem que não existem períodos sensíveis para a ocorrência de lesões em virtude de desequilíbrios musculares ao longo do MP em jogadores de futebol da categoria sub-20.The objective of the present study was to evaluate the muscular balance of knee flexors and extensors (RFE) in under-20 soccer players during a training season. 15 under-20 subjects from the Ponte Preta Athletic Association of Campinas participated in a 29 week macrocycle preparation (MP), composed of preparatory and competitive periods which were divided into four mesocycles: general stage (M1), special stage (M2), pre-competitive stage (M3) and competitive stage (M4). RFE of both members was determined with the torque peak (TP) obtained in isokinetic dynamometer in three consecutive sets of five repetitions of 60 degrees/s. Isokinetic evaluation was accomplished in four stages along the MP at the end of each mesocycle (M1, M2, M3, and M4). Statistic analysis was performed using the Friedman test with repeated measures, followed by Wilcoxon test and Mann-Whitney U test, with significance level of p<0.05. TP of knee flexors muscles in both members were greater in M2 and M3 than in M1 and M4. TP of knee extensors in M1 was significantly inferior than the other stages of the study (M2, M3, and M4), in both members. RFE, in both members, was inferior in M1 when compared to M2 and M3. RFE comparison among members did not reveal significant differences in any moment of the study (M1, M2, M3, and M4). The results indicated the existence of alterations in the size of RFE; within normality though, and maintenance of the proportionality among members along the MP. These results suggest that there are not sensitive periods to the occurrence of injuries due to muscular imbalances along MP in under-20 soccer players

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

Effects of Isometric Handgrip Training in Patients With Peripheral Artery Disease: A Randomized Controlled Trial

BackgroundMeta‐analyses have shown that isometric handgrip training (IHT) can reduce brachial systolic and diastolic blood pressure (BP) by >6/4 mm Hg, respectively. However, whether IHT promotes these effects among patients with peripheral artery disease, who exhibit severe impairment in cardiovascular function, is currently unknown. This study aimed to evaluate the effects of IHT on the cardiovascular function of patients with peripheral artery disease. Methods and ResultsA randomized controlled trial with peripheral artery disease patients assigned to either the IHT or control group was conducted. The IHT group performed 3 sessions per week, for 8 weeks, of unilateral handgrip exercises, consisting of 4 sets of isometric contractions for 2 minutes at 30% of maximum voluntary contraction and a 4‐minute interval between sets. The control group received a compression ball in order to minimize the placebo effects, representing sham training. The primary outcome was brachial BP. The secondary outcomes were central BP, arterial stiffness parameters, cardiac autonomic modulation, and vascular function. The IHT program reduced diastolic BP (75 [10] mm Hg preintervention versus 72 [11] mm Hg postintervention), with no change in the control group (74 [11] mm Hg preintervention versus 74 [11] mm Hg postintervention), with this between‐group difference being significant (P=0.04). Flow‐mediated dilation improved in the IHT group (6.0% [5.7] preintervention versus 9.7% [5.5] postintervention), with no change in the control group (7.6% [5.5] preintervention versus 7.4% [5.1] postintervention), with this between‐group difference being significant (P=0.04). There was no change in other measured variables over the intervention period. ConclusionsIHT reduced brachial diastolic BP and improved local vascular function in patients with peripheral artery disease

Eccentric Strength and Endurance in Patients with Unilateral Intermittent Claudication

OBJECTIVE: To analyze concentric and eccentric strength and endurance in patients with unilateral intermittent claudication. INTRODUCTION: Basic motor tasks are composed of concentric, isometric, and eccentric actions, which are related and contribute to physical performance. In previous studies of patients with intermittent claudication, the disease-related reduction in concentric and isometric muscular strength and endurance resulted in poorer walking performance. To date, no study has evaluated eccentric muscle action in patients with intermittent claudication. METHODS: Eleven patients with unilateral intermittent claudication performed isokinetic concentric and eccentric actions at the ankle joints to assess peak torque and total work in both symptomatic and asymptomatic legs. RESULTS: Concentric peak torque and total work were lower in the symptomatic than in the asymptomatic leg (80 ± 32 vs. 95 ± 41 N/m, P = 0.01; 1479 ± 667 vs. 1709 ± 879 J, P = 0.03, respectively). There were no differences in eccentric peak torque and total work between symptomatic and asymptomatic legs (96 ± 30 vs. 108 ± 48 N/m; 1852 ± 879 vs. 1891 ± 755 J, respectively). CONCLUSION: Strength and endurance in the symptomatic leg were lower during concentric compared to eccentric action. Future studies are recommended to investigate the mechanisms underlying these responses and to analyze the effects of interventions to improve concentric strength and endurance on functional limitations in patients with intermittent claudication

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)

Resistance training as a treatment for older persons with peripheral artery disease: A systematic review and meta-analysis

Objective: Resistance training (RT) improves walking ability in persons with peripheral artery disease. We conducted a meta-analysis of randomised controlled trials (RCTs) investigating the effect of RT on peripheral artery disease (as measured by walking ability). Design: We included RCTs that investigated the effect of RT on treadmill and/or 6 min walk (6-MWT) distances. RT intensity was assessed according to the American College of Sports Medicine guidelines by 1 repetition maximum or rating of perceived exertion. Standardised mean (SMD) and mean differences (MD) were calculated using a random-effects inverse variance model. Heterogeneity and bias were assessed using RevMan V.5.3. Meta-regression and meta-analysis of variance were performed as moderator analyses. Data sources: Databases (Medline, Embase, Web of Science, Cinahl and Google Scholar) were searched until July 2018. Results: Fifteen trials isolated RT; 7 trials compared RT with aerobic exercise. We analysed 826 patients (n=363 completing RT), with a mean age of 67.1±3.8 years. Training ranged from low-high intensity, 2-7 times per week for 17±7 weeks, with a mix of upper, lower or whole body training. Overall RT significantly improved constant load treadmill claudication onset (COD) (SMD 0.66 [0.40, 0.93],

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