Efeitos do treinamento concorrente com e sem a execução de repetições até a falha concêntrica nas adaptações neuromusculares e funcionais em homens idosos

O treinamento concorrente é conhecido como uma alternativa eficiente para promover diversos benefícios fisiológicos além de minimizar os prejuízos causados pelo envelhecimento. Diferentes métodos têm sido investigados com o intuito de otimizar os ganhos gerados pelo treinamento, a partir disso, o treinamento de força com o uso de repetições até a falha concêntrica tem recebido considerável atenção por parte dos pesquisadores. Os resultados encontrados na literatura mostram-se controversos e existem escassos estudos comparando o uso de repetições máximas e submáximas em indivíduos idosos, principalmente em períodos mais longos de intervenção. Assim, o objetivo do presente estudo foi comparar os efeitos do treinamento concorrente com e sem a execução de repetições até a falha concêntrica nas adaptações neuromusculares e funcionais em homens idosos. Métodos: 36 homens idosos sedentários (67,1 ± 5,1 anos) foram randomizados em três grupos: grupo com repetições até a falha (RFG, n = 13), grupo com repetições sem a falha e 50% do volume de treino de RFG (NFG, n = 12), e grupo com repetições sem a falha mas com volume equalizado ao RFG (ENFG, n = 11). Os protocolos de treinamento ocorreram 2 vezes por semana, durante 20 semanas. Durante a sessão de treino, os indivíduos iniciavam com exercícios de força e em seguida realizavam exercício aeróbico em esteira rolante. Foram realizadas avaliações de uma repetição máxima (1RM) nos exercícios de leg press e extensão de joelhos, pico de torque isométrico (PTiso), taxa de produção de torque (TPT) em 50, 100 e 250ms e espessura muscular do vasto lateral, vasto medial, vasto intermédio e reto femoral, também foi avaliada a capacidade funcional através dos testes de sentar e levantar da cadeira e timed up and go (TUG) antes e depois do período de intervenção. Resultados: Após 20 semanas de treinamento, houve incrementos significativos nos valores de 1RM em leg press e extensão de joelhos (p<0,001), no PTiso (p<0,001), na TPT (50, 100 e 250ms) (p≤0,001), na espessura muscular do quadríceps (p<0,05) e no teste de sentar e levantar da cadeira (p<0,05) em todos os grupos, sem diferença significativa entre eles. Conclusão: Os resultados sugerem que o treinamento concorrente com o uso de repetições até a falha concêntrica não promove benefícios adicionais na função muscular e na capacidade funcional de indivíduos idosos. Além disso, realizar exercícios com metade do volume de treinamento com moderada e alta intensidade (65-80% de 1RM) parece otimizar as adaptações neuromusculares e funcionais após 20 semanas de treinamento

Efeitos de uma intervenção de exercício multicomponente na função neuromuscular em pacientes idosos agudamente hospitalizados

O período de internação pode ocasionar impactos negativos em pacientes idosos hospitalizados. A redução dos níveis habituais de atividade física devido ao longo período de repouso no leito e as modificações que ocorrem nas práticas alimentares durante os dias de hospitalização provocam prejuízos na função física e na independência funcional para a realização das atividades de vida diária. Aproximadamente metade dos idosos hospitalizados apresenta condições de (pré-) fragilidade, (pré-) sarcopenia ou (risco de) desnutrição durante a hospitalização, levando ao aumento do uso de fármacos, dias de internação, readmissão hospitalar e risco de mortalidade por diversas causas. A alta prevalência de tais condições debilitantes justifica a necessidade de avaliações padronizadas e da elaboração de tratamentos que promovam um suporte nutricional adequado e de programas de exercícios físicos supervisionados que possam minimizar os riscos associados à internação em idosos agudamente hospitalizados. Objetivo: a) determinar os efeitos de intervenções nutricionais e de exercícios físicos na função física, independência funcional e parâmetros clínicos de idosos agudamente hospitalizados. b) Investigar os efeitos de uma intervenção de exercício multicomponente de curto prazo na força máxima e potência muscular em idosos hospitalizados. Para isso, o seguinte trabalho será apresentado em dois capítulos: I - Busca na literatura, síntese de dados e análises de estudos com intervenções nutricionais e de exercícios físicos sobre parâmetros funcionais e clínicos de idosos hospitalizados; II - ensaio clínico com idosos hospitalizados randomizados em grupo de cuidados usuais (controle) ou grupo de treinamento com exercícios multicomponentes (grupo intervenção). A pesquisa ocorreu em uma unidade de terapia intensiva em um hospital público terciário (Navarra, Espanha), com sessões de treinamento contendo exercícios de força, equilíbrio e marcha durante 3 dias consecutivos. Avaliações de força máxima muscular (legpress e supino) e potência muscular (legpress) ocorreram nas primeiras 48 horas de admissão hospitalar e após 3 dias, antes da alta hospitalar. Conclusão: I – Intervenção com exercícios físicos melhorou a independência funcional de idosos agudamente hospitalizados, ao passo que, intervenções nutricionais e de exercícios físicos não promoveram modificações na função física muscular e em parâmetros clínicos de idosos hospitalizados; II - Um programa de exercícios de curto prazo, individualizado e multicomponente, realizado em dias consecutivos, promove incrementos na força e potência muscular em pacientes idosos hospitalizados agudamente

Speed, agility, and musculoskeletal fitness are independently associated with areal bone mineral density in children

Background: There is still little understanding of the associations between physical fitness variables and bone health in children taking into account key confounders. Aim: The aim of this study was to analyze the associations between performance in tests of speed, agility, and musculoskeletal fitness (power of the upper and lower limbs) with bone mass of different regions in children, considering the adjustment to maturity-offset, lean percentage, and sex. Methods: Cross-sectional study design: the sample consisted of 160 children aged 6–11 years. The physical fitness variables tested were 1) speed, assessed with the running test at a maximum speed of 20 m; 2) agility, assessed through the 4×4-m square test; 3) lower limb power, assessed using the standing long jump test, and 4) upper limb power, assessed using the 2-kg medicine ball throw test. Areal bone mineral density (aBMD) was obtained from the analysis of body composition by dualenergy X-ray absorptiometry (DXA). Simple and multiple linear regression models were performed using the SPSS software. Results: In the crude regression analyses, the results indicated a linear relationship between all the physical fitness variables and aBMD in all body segments, but maturity-offset, sex, and lean mass percentage seemed to have an effect on these relationships. Except for the upper limb power, the other physical capacities (speed, agility, and lower limb power) were associated with aBMD in at least three body regions in the adjusted analyses. These associations occurred in the spine, hip, and leg regions, and the aBMD of the legs presented the best association magnitude (R2 ). Conclusion: There is a significant association between speed, agility, and musculoskeletal fitness, specifically the lower limb power and aBMD. That is, the aBMD is a good indicator of the relationship between fitness and bone mass in children, but it is essential to consider specific fitness variables and skeletal regions

Thermoregulation during exercise in the heat of American football players

American football players might face challenges during a prolonged exercise in the heat which can lead to impairments in performance and induce heat-related illness. The purpose of this study was to verify the body temperature and sweating responses in American football players while exercising at a moderate-high intensity effort as prescribed by metabolic heat production. Seven heat-acclimatized players participated in the study. Players exercised 4×20-min bouts at moderate-high intensity as 8.0W.kg-1 of metabolic heat production, with 10min rest between them, totalizing 110min of heat exposure (39oC and 50% relative humidity). Rectal (Tre) and skin (Tsk) temperatures, heart rate (HR), metabolic heat production were measured continuously. Dehydration was calculated from Δbody mass pre-and post-exercise. Initial Tre and HR were 37.0 ± 0.3 °C and 80 ± 9 beats.min-1, respectively. Players began the trial euhydrated according to the initial urine specific gravity (1.014 ± 0.008) and colour (2.4 ± 1.4). During experimental trial, core temperature increased overtime (p < .001) resulting in a ΔTre of 2.2 ± 0.6 °C. Average HR during exercise was 166 ± 11 beats.min-1 and weighted Tsk was 36.7 ± 0.5 °C. Sweat volume was 2.6 ± 0.3 L, resulting a % hypohydration of -3.1 ± 0.4 % reflecting a moderate level of hypohydration. Final urine specific gravity and colour were 1.024 ± 0.009 and 5.0 ± 1.0, respectively. Experimental trials were interrupted at the end of the third and the fourth exercise bouts in two players due to the respective adverse conditions: leg muscle cramps, and excessive Tre increase (reached 39.9 °C). Thermoregulation and hydration must be a major concern, mainly related to greater exercise intensities and long-time practice, inducing high hypohydration levels and risk of hyperthermia

Comparison of muscle quality and functional capacity between Japanese and Brazilian older individuals

Muscle quality is well-known to decrease with aging and is a risk factor for metabolic abnormalities. However, there is a lack of information on race-associated differences in muscle quality and other neuromuscular features related to functional performance. This study aimed to compare muscle quality, function, and morphological characteristics in Japanese and Brazilian older individuals. Eighty-four participants aged 65–87 years were enrolled in the study (42 Japanese: 23 men, 19 women, mean age 70.4 years; 42 Brazilians: 23 men, 19 women, mean age 70.8 years). Echo intensity (EI) and muscle thickness (MT) of the quadriceps femoris were measured using B-mode ultrasonography. A stepwise multiple linear regression analysis with EI as a dependent variable revealed that MT was a significant variable for Japanese participants (R2 = 0.424, P = 0.001), while MT and subcutaneous adipose tissue (SCAT) thickness were significant variables for Brazilian participants (R2 = 0.490, P = 0.001). A second stepwise multiple linear regression analysis was performed after excluding MT and SCAT thickness from the independent variables. Sex and age for Japanese participants (R2 = 0.381, P = 0.001) and lean body mass and body mass index for Brazilian participants (R2 = 0.385, P = 0.001) were identified as significant independent variables. The present results suggest that MT is closely correlated with muscle quality in Japanese and Brazilian older individuals. Increases in muscle size may induce decreases in intramuscular adipose tissue and/or connective tissues, which are beneficial for reducing the risks of metabolic impairments in Japanese and Brazilian older individuals

Association between physical exercise interventions participation and functional capacity in individuals with type 2 diabetes : a systematic review and meta-analysis of controlled trials

Background: The prevalence of type 2 diabetes mellitus increases with age, and people with type 2 diabetes are more affected by reductions in functional performance. Although exercise interventions are recommended for people with diabetes, it is relevant to assess the effects of different training modes on the available functional outcomes. Therefore, our purpose was to systematically assess the effect of different physical exercise modalities in patients with type 2 diabetes with an average age of 45 years or older on outcomes used to measure functional capacity. Methods: A systematic review and meta-analysis of controlled trials was conducted. Seven databases were searched from January 1987 to December 2021 (PubMed, Physiotherapy Evidence Database, Cochrane Library, SPORTDiscus, and in grey literature: Open Grey and Google Scholar). Eligible studies should last 8 weeks or longer, comparing structured exercise training and non-exercise control for one out of six pre-specified functional capacity outcomes (Timed Up and Go test, chair stands, walking performance, upper-limb muscle strength, lower-limb muscle strength, physical fitness parameter), in patients with type 2 diabetes, aged ≥ 45 years. The risk of bias was assessed with the Downs & Black checklist. Pooled mean differences were calculated using a random-effects model, followed by sensitivity and meta-regression analyses. Results: Of 18,112 references retrieved, 29 trials (1557 patients) were included. Among these, 13 studies used aerobic training, 6 studies used combined training, 4 studies used resistance training, 3 studies had multiple intervention arms and 3 studies used other types of training. Exercise training was associated with an increase in functional capacity outcomes, as reflected by changes in 6-min walk test (n = 8) [51.6 m; 95% CI 7.6% to 95.6%; I2 92%], one-repetition maximum leg-press (n = 3) [18.0 kg; 95% CI 4.0% to 31.9%; I2 0%], and maximum oxygen consumption (VO2max) (n = 20) [2.41 mL/kg·min; 95% CI 1.89% to 2.92%; I2 100%] compared with control groups. In sensitivity and subgroup analyses using VO2max as outcome and stratified by type of study (randomized and non-randomized controlled clinical trials), duration of diabetes diagnosis, and sex, we observed overlapping confidence intervals. Meta-regression showed no association between glycated hemoglobin (HbA1C) levels and VO2max [p = 0.34; I2 99.6%; R2 = 2.6%]. In addition, the quality of the included studies was mostly low. Conclusion: The results indicate that structured physical exercise programs might improve functional capacity in patients with type 2 diabetes, except for the upper-limb muscle strength. However, we could not identify potential effect predictors associated with directional summary estimates

Cardiometabolic health profle of young girls with aesthetic professions

Background: In the literature, professions that impose body standards for daily performance are designated as nonconventional professions (i.e. models, athletes, ballet dancers), with great emphasis on the female population. More than a job, it becomes a lifestyle to those inserted in this environment, thus, thousands of children and adolescents seek inclusion and success in these professions due to fnancial and media gains. Such professions are associated with several health-related risk factors. The purpose of this study was to identify and compare among physical ftness levels, cardiometabolic health markers, mental health and dietary habits in non-conventional professions. Methods: The sample consisted of 41 female individuals aged between 14 and 24 years, allocated into four groups, control group composed by university students (UG=11), models (MG=11), ballet dancers (BG=11), and athletes’ group (AG=8). Physical ftness outcomes (cardiorespiratory ftness, fexibility, maximal dynamic strength, muscular endurance and body composition); biochemical outcomes (high-density lipoprotein [HDL], low-density lipoprotein [LDL], total cholesterol [TC], fasting glucose [FG], fasting insulin [FI], C-reactive protein [CRP]), diet quality and mental health were evaluated. Results: No impairments were observed in the health markers evaluated among groups, both for health-related physical ftness and biochemical outcomes. However, low levels of bone mineral density (BMD) were observed. Even with statistically signifcant diferences between the groups for chronological age (p=0.002), menarche (p=0.004), career length (p=0.001), height (p=0.001), body mass index (p=0.018), waist-to-height ratio (p<0.001), %Fat (p=0.020), VO2peak (p=0.020), maximal dynamic strength of knee extensors (p=0.031) and elbow fexors (p=0,001) and fexibility (p<0.001), all these values are within the normal range for health. Conclusion: The professions analyzed do not seem to interfere in the physical ftness and cardiometabolic health of the girls assessed. However, we identifed that exposure to these profession can impair mental health (depressive symptoms in 100% of participants) and body composition (BMD 63% of participants)

Effects of high-intensity interval training combined with traditional strength or power training on functionality and physical fitness in healthy older men : a randomized controlled trial

Concurrent training (CT) is an efficient strategy to improve neuromuscular function and cardiorespiratory fitness in older adults, which are factors of pivotal importance for the maintenance of functional capacity with aging. However, there is a lack of evidence about the effectiveness of power training (PT) as an alternative to traditional strength training (TST) during CT. Thus, the aim of the present study was to examine the effect of 16 weeks (twice weekly) TST combined with high intensity interval training (TST + HIIT) vs. PT combined with HIIT (PT + HIIT) on functional performance, cardiorespiratory fitness and body composition in older men. Thirty five older men (65.8 ± 3.9 years) were randomly allocated into two training groups: TST + HIIT (n = 18), and PT + HIIT (n = 17). TST + HIIT performed resistance training at intensities ranging from 65% to 80% 1RM at slow controlled speed (≅ 2 s for each concentric phase), whereas PT + HIIT trained at intensities ranging from 40% to 60% of 1RM at maximal intentional speed. Both groups performed HIIT at intensities ranging from 75 to 90% of VO2peak. Participants performed functional tests (sit-to-stand, timed-up-and-go, stair climbing); cardiopulmonary exercise testing (maximal cycling power output: Wmax, peak oxygen uptake: VO2peak, cycling economy), as well as body composition assessment (DXA) before, post 8 and post 16 weeks of training. The groups improved similarly (P < 0.05) with training in all functional capacity outcomes, Wmax, cycling economy, VO2peak and body composition (P < 0.05). These findings suggest that HIIT based CT programs involving TST vs. PT are equally effective in improving functionality, cardiorespiratory fitness and body composition in healthy older men