Prediction equation of peak oxygen uptake for the modified shuttle test in healthy adolescents / Equação de predição do consumo máximo de oxigênio para o shuttle test modificado em adolescentes saudáveis / Ecuación de predicción del consumo máximo de oxígeno para el shuttle test modificado en adolescentes sanos

ABSTRACT Given the gap in the literature regarding the peak of oxygen consumption (VO2peak) for adolescents of both sexes, this study aimed to propose an equation to predict the VO2peak in healthy adolescents using the Modified Shuttle Test (MST). This is a cross-sectional study with 84 healthy adolescents between 12 and 18 years old, female and male. The MST is an external paced test, in which the speed increases at each minute. Two MST were performed with at least 30 minutes of rest between them. The test with the longest walked distance was considered for analysis. VO2 was directly monitored by an open circuit spirometry. Mean age was 14.67±1.82 and the walked distance was 864.86±263.48m. Variables included in the prediction equation were walked distance and sex, explaining the VO2peak variability of 53% during MST performance. The prediction equation for VO2peak with the MST was: predicted VO2peak=18.274+(0.18×Distance Walked, meters)+(7.733×Sex); R2=0.53 and p<0.0001 (sex: 0 for girls, 1 for boys). This MST equation, proposed to predict VO2peak in healthy adolescents of both sexes, can be used as a reference to assess exercise capacity in healthy adolescents and to investigate cardiopulmonary function in adolescents with reduced functional capacity.

RESUMO Dada a lacuna na literatura quanto à equação de predição do pico de consumo de oxigênio (VO2) para adolescentes de ambos os sexos, o objetivo deste estudo é propor uma equação para predizer o VO2pico em adolescentes saudáveis utilizando o shuttle test modificado (MST). Trata-se de um estudo transversal realizado com 84 adolescentes saudáveis entre 12 e 18 anos, do sexo feminino e masculino. O MST é um teste de campo ditado por um sinal sonoro que indica o aumento da velocidade a cada minuto. Dois MSTs foram realizados com pelo menos 30 minutos de descanso entre eles. O teste com a maior distância percorrida foi o considerado para análise. O VO2 foi monitorado diretamente por uma espirometria de circuito aberto. A média de idade foi de 14,67±1,82 anos, e a de distância percorrida foi de 864,86±263,48m. As variáveis incluídas na equação de predição foram distância percorrida e sexo, que explicaram 53% da variabilidade do VO2pico durante a realização do MST. A equação de referência para o VO2pico previsto com o MST foi VO2pico predito=18,274+(0,18×Distância percorrida, em metros)+(7,733×Sexo); R2=0,53 e p<0,0001 (sexo: 0 para meninas, 1 para meninos). A equação do MST proposta para predizer o VO2pico em adolescentes saudáveis de ambos os sexos pode ser usada como referência para avaliar a capacidade de exercício em adolescentes saudáveis e investigar a função cardiopulmonar em adolescentes com capacidade funcional reduzida.

RESUMEN Dada una laguna en la literatura con respecto a la ecuación para predecir el consumo máximo de oxígeno (VO2) en adolescentes de ambos sexos, el objetivo de este estudio es proponer una ecuación para predecir el VO2máximo en adolescentes sanos usando el shuttle test modificado (MST). Se trata de un estudio transversal, realizado con 84 adolescentes sanos con edades entre 12 y 18 años, de ambos sexos. El MST es una prueba de campo dictada por una señal sonora que indica el aumento de velocidad cada minuto. Se realizaron dos MST con al menos 30 minutos de descanso entre ellos. Para el análisis se consideró la prueba con mayor distancia recorrida. El monitoreo del VO2 fue realizado directamente por espirometría de circuito abierto. La edad media fue de 14,67±1,82 años; y la distancia recorrida, de 864,86±263,48m. Las variables incluidas en la ecuación de predicción fueron la distancia recorrida y el sexo, que explicaron el 53% de la variabilidad del VO2máximo durante la realización del MST. La ecuación de referencia para el VO2máximo predicho con el MST fue VO2máximo previsto=18,274+(0,18×Distancia recorrida, en metros)+(7,733×Sexo); R2=0,53 y p<0,0001 (sexo: 0 para chicas, 1 para chicos). La ecuación MST propuesta para predecir el VO2máximo en adolescentes sanos de ambos sexos puede utilizarse como una referencia para evaluar la capacidad de ejercicio en adolescentes sanos y para investigar la función cardiopulmonar en adolescentes con capacidad funcional reducida.

Adiponectin Is a Contributing Factor of Low Appendicular Lean Mass in Older Community-Dwelling Women: A Cross-Sectional Study.

Inflammation is a chronic, sterile, low-grade inflammation that develops with advanced age in the absence of overt infection and may contribute to the pathophysiology of sarcopenia, a progressive and generalized skeletal muscle disorder. Furthermore, a series of biomarkers linked to sarcopenia occurrence have emerged. To aid diagnostic and treatment strategies for low muscle mass in sarcopenia and other related conditions, the objective of this work was to investigate potential biomarkers associated with appendicular lean mass in community-dwelling older women. This is a cross-sectional study with 71 older women (75 ± 7 years). Dual-energy X-ray absorptiometry was used to assess body composition. Plasmatic blood levels of adipokines (i.e., adiponectin, leptin, and resistin), tumor necrosis factor (TNF) and soluble receptors (sTNFr1 and sTNFr2), interferon (INF), brain-derived neurotrophic factor (BDNF), and interleukins (IL-2, IL-4, IL-5, IL-6, IL-8, and IL-10) were determined by enzyme-linked immunosorbent assay. Older women with low muscle mass showed higher plasma levels of adiponectin, sTNFr1, and IL-8 compared to the regular muscle mass group. In addition, higher adiponectin plasma levels explained 14% of the lower appendicular lean mass. High adiponectin plasmatic blood levels can contribute to lower appendicular lean mass in older, community-dwelling women.

Avaliação da força muscular respiratória em adultos cantores de coral e não cantores / Evaluación de la fuerza muscular respiratoria en adultos cantantes de coro y no cantantes / Assessment of respiratory muscle strength in adult choir singers and non-singers

RESUMO Um bom desempenho musical exige dos cantores alta habilidade do sistema respiratório, uma vez que, durante o canto, a musculatura respiratória produz o aumento e diminuição da caixa torácica. O objetivo deste estudo foi verificar e comparar a força muscular respiratória de indivíduos adultos cantores de coral e não cantores. Trata-se de uma pesquisa transversal, composta por indivíduos com idade entre 18 a 45 anos, de ambos os sexos, sedentários e não tabagistas, distribuídos entre dois grupos: indivíduos cantores de coral (GC; n=23) e indivíduos não cantores (GNC; n=23). Os grupos foram avaliados quanto à força muscular inspiratória (pressão inspiratória máxima - PImáx.) e expiratória (pressão expiratória máxima - PEmáx.) por meio da manovacuometria. Indivíduos do GC apresentaram valores maiores da PImáx. (p=0,049) e PEmáx. (p<0,001) quando comparados ao GNC. Além disso, identificou-se que os valores da PImáx. têm magnitude de efeito e poder moderados (d=0,56; poder=0,59), e os valores da PEmáx. magnitude de efeito moderado e poder elevado (d=0,77; poder=0,82). Essa diferença das medidas de PImáx. e PEmáx. entre GNC e GC foi também observada ao se considerar os valores dos percentuais dos preditos (p<0,05). A partir das análises realizadas, conclui-se que cantores adultos de coral apresentam maior força muscular inspiratória e expiratória quando comparados a não cantores.

RESUMEN Para un buen desempeño musical, los cantantes necesitan tener una alta capacidad pulmonar, ya que los músculos respiratorios durante el canto producen un aumento y disminución de la caja torácica. El objetivo de este estudio fue verificar y comparar la fuerza muscular respiratoria entre individuos adultos cantantes de coro y no cantantes. Este es un estudio transversal, en el que participó individuos con edades comprendidas entre 18 y 45 años, de ambos los sexos, sedentarios y no fumadores, que fueron distribuidos en dos grupos: cantantes de coro (GC; n=23) y no cantantes (CNG; n=23). Los grupos se sometieron a evaluación de la fuerza muscular inspiratoria (presión inspiratoria máxima, PImáx.) y espiratoria (presión espiratoria máxima, PEmáx.) mediante manovacuometría. Los individuos del GC presentaron valores más altos de PImáx. (p=0,049) y de PEmáx. (p<0,001) que los de GNC. Además, se identificó que los valores de PImáx. tienen magnitud del efecto y potencia moderados (d=0,56; potencia=0,59), y los valores de PEmáx, magnitud de efecto moderado y alta potencia (d=0,77; potencia=0,82). Esta diferencia en las mediciones de PImáx. y PEmáx. entre GNC y GC también se observó al considerar los valores de los porcentajes de los predichos (p<0,05). De los análisis realizados se concluye que los adultos cantantes de coro tienen mayor fuerza muscular inspiratoria y espiratoria que los no cantantes.

ABSTRACT A good musical performance requires singers to have high respiratory system skills since the respiratory muscles produce an increase and decrease in the rib cage during singing. Our research aimed to verify and compare the respiratory muscle strength of adult choir singers and non-singers. This is a cross-sectional study consisting of individuals between 18 and 45 years of age, of both sexes, sedentary and non-smokers, distributed between two groups: choir singers (GC; n=23) and non-singers (GNC; n=23). Both groups were evaluated for inspiratory (maximal inspiratory pressure - MIP) and expiratory (maximal expiratory pressure - MEP) muscle strength through a manovacuometer. Individuals in the GC showed higher values of MIP (p=0.049) and MEP (p <0.001) when compared to the GNC. Moreover, MIP values were identified as having a moderate magnitude of effect and power (d=0.56; power=0.59), whereas MEP values had a moderate magnitude of effect and high power (d=0.77; power=0.82). This difference in MIP and MEP measurements between GNC and GC was also observed regarding values of the predicted percentages (p<0.05). From the analyzes performed, one can conclude that adult choir singers have greater inspiratory and expiratory muscle strength when compared to non-singers.

Cortisol secretion pattern in overweight/obese and normal-weight infants: a cross-sectional study.

Background The salivary circadian diurnal cortisol plays an important role in growth and development. Inappropriate levels may induce changes associated with an increased risk of obesity later in life. It is unknown if there are differences in cortisol secretion pattern between overweight/obese infants when compared with theirs peers in infancy. Thus, this study aimed to compare the salivary cortisol secretion pattern in overweight/obese and normal-weight infants. Methods Thirty-three (overweight/obese = 17 and normal weight = 16) infants between 6 and 24 months of age had saliva samples collected upon awakening (T1), 30 min after waking (T2), at 12:00 am or before the baby's meal (T3), and prior to bedtime (T4). Highly sensitive enzyme immunoassays were used for cortisol analyses. Results Salivary cortisol levels were similar between the groups: T1 (p = 0.22; 95% confidence interval [CI]: -5.65, 1.37), T2 (p = 0.24; 95% CI: -8.23, 2.17), T3 (p = 0.95; 95% CI: -3.16, 2.96), and T4 (p = 0.81; 95% CI: -1.39, 1.08); and no differences were observed between area under the curve (AUC) (p = 0.80; 95% CI: -4.58-13.66). The cortisol level reduced in T4 (95% CI: 1.35-2.96) compared to T1 (95% CI: 5.15-8.49) and T2 in the overweight/obese group (p < 0.001; 95% CI: 6.02-11.04). In the normal-weight group, the cortisol reduced in T3 (95% CI: 2.86-8.18) compared to T1 (95% CI: 5.64-12.28) and decreased until T4 (p = 0.001; 95% CI: 1.25-3.37). Conclusions The overweight/obese infant group presented a different pattern of cortisol secretion, although cortisol levels did not differ between the control group.

Whole Body Vibration Training on Muscle Strength and Brain-Derived Neurotrophic Factor Levels in Elderly Woman With Knee Osteoarthritis: A Randomized Clinical Trial Study.

Background: Osteoarthritis of the knee (kOA) is a chronic, progressive, degenerative health condition that contributes to the imbalance between the synthesis and destruction of articular cartilage. Recently, whole body vibration (WBV) training has been recommended as an effective alternative for strength training in elderly people, and various physiological effects are obtained in response to exercise performed on a vibratory platform, such as an increase in muscle activation and improved muscle performance. However, the effects of WBV particularly on the strength of the quadriceps muscle and neuronal plasticity are unknown. Objective: The aim of this study was to evaluate the effects of adding WBV to squat training on the isometric quadriceps muscle strength (IQMS) and the plasma levels of brain-derived neurotrophic factor (BDNF) in elderly woman with kOA. Methods: Fifteen elderly women ≥65 years of age with kOA were randomized into two interventions: (1) the vibration group (VG), in which participants performed squat exercise training in association with WBV or (2) the exercise group (EG), in which participants performed squat exercise training without vibration, for 12 weeks 3×/week. Results: Compared to the EG group, the VG group demonstrated a significantly greater delta (Δ) in IQMS values (IC95% 0.43-7.06; p ≤ 0.05) and in Δ BDNF plasma levels (IC95% -32.51 to 4.217; p ≤ 0.05) after the intervention period. There was an association between increase of Δ BDNF plasma levels and increase of Δ IQMS (ß = 0.57; R 2 = 0.32; p = 0.03). Conclusion: The addition of WBV to squat exercise training improves lower limb muscle performance in elderly women with kOA. These findings suggest that the improvement in muscle performance is related to neuromuscular adaptations induced by WBV. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03918291.

Cardiorespiratory fitness assessment and prediction of peak oxygen consumption by Incremental Shuttle Walking Test in healthy women.

INTRODUCTION: Preliminary studies have showed that the Incremental Shuttle Walking Test (ISWT) is a maximal test, however comparison between ISWT with the cardiopulmonary exercise test (CEPT) has not yet performed in the healthy woman population. Furthermore, there is no regression equation available in the current literature to predict oxygen peak consumption (VO2 peak). Thus, this study aimed to compare the ISWT with CEPT and to develop an equation to predict peak oxygen uptake (VO2 peak) in healthy women participants. METHODS: First, the VO2 peak, respiratory exchange ratio (R peak), heart rate max (HR max) and percentage of predicted HR max (% predicted HR max) were evaluated in the CEPT and ISWT (n = 40). Then, an equation was developed to predict the VO2 peak (n = 54) and its validation was performed (n = 20). RESULTS: There were no significant differences between the ISWT and CEPT of VO2 peak, HR max and % predicted HR max values (P>0.05), except for R peak measure in the ISWT (1.22 ± 0.13) and CEPT (1.18 ± 0.1) (P = 0.022). Therefore, both tests showed a moderate positive correlation of VO2 peak (r = 0.51; P = 0.0007), HR max (r = 0.65; P<0.0001) and R peak (r = 0.55; P = 0.0002) and the Bland-Altman analysis showed agreement of VO2 peak (bias = -0.14). The distance walked on ISWT and age explained 36.3% (R2 Adjusted = 0.363) of the variance in VO2 peak. The equation developed was VO2 peak (predicted) = 19.793 + (0.02 x distance walked)-(0.236 x age). There was no statistically significant difference between the VO2 peak measured directly and the predicted, and the Bland-Altman analysis showed agreement (bias = 1.5 ml/kg/min). CONCLUSION: ISWT is a maximal test showing similar results compared to the CEPT, and the predicted equation was valid and applicable for VO2 peak assessing in young adult healthy women.

The role of the inspiratory muscle weakness in functional capacity in hemodialysis patients.

INTRODUCTION: Inspiratory muscle function may be affected in patients with End-Stage Renal Disease (ESRD), further worsening the functional loss in these individuals. However, the impact of inspiratory muscle weakness (IMW) on the functional capacity (FC) of hemodialysis patients remains unknown. Thus, the present study aimed to evaluate the impact of IMW on FC in ESRD patients undergoing hemodialysis. MATERIALS AND METHODS: ESRD patients on hemodialysis treatment for more than six months were evaluated for inspiratory muscle strength and FC. Inspiratory muscle strength was evaluated based on maximal inspiratory pressure (MIP). IMW was defined as MIP values less than 70% of the predicted value. FC was evaluated using the Incremental Shuttle Walk test (ISWT). Patients whose predicted peak oxygen uptake (VO2peak) over the distance walked during the ISWT was less than 16mL/kg/min were considered to have FC impairment. Associations between variables were assessed by linear and logistic regression, with adjustment for age, sex, body mass index (BMI), presence of diabetes and hemoglobin level. Receiver-operating characteristic (ROC) analysis was used to determine different cutoff values of the MIP for normal inspiratory muscle strength and FC. RESULTS: Sixty-five ERSD patients (67.7% male), aged 48.2 (44.5-51.9) years were evaluated. MIP was an independent predictor of the distance walked during the ISWT (R2 = 0.44). IMW was an independent predictor of VO2peak < 16mL/kg/min. (OR = 5.7; p = 0.048) in adjusted logistic regression models. ROC curves showed that the MIP cutoff value of 82cmH2O had a sensitivity of 73.5% and specificity of 93.7% in predicting normal inspiratory strength and a sensitivity and specificity of 76.3% and 70.4%, respectively, in predicting VO2peak ≥ 16mL/kg/min. CONCLUSIONS: IMW is associated with reduced FC in hemodialysis patients. Evaluation of the MIP may be important to functional monitoring in clinical practice and can help in the stratification of patients eligible to perform exercise testing.

Neuroendocrine Inflammatory Responses in Overweight/Obese Infants.

Childhood obesity is related to a cascade of neuroendocrine inflammatory changes. However, there remains a gap in the current literature regarding the possible occurrence of these changes in overweight/obese infants. The objective of this study was to evaluate adipokines, cortisol, brain-derived neurotrophic factor (BDNF) and redox status in overweight/obese infants versus normal-weight peers. A cross-sectional study was conducted with 50 infants (25 in the overweight/obese group and 25 in the normal-weight group) between 6 and 24 months. Plasma levels of leptin, adiponectin, resistin, soluble tumor necrosis factor (TNF) receptors, chemokines, BDNF, serum cortisol and redox status were measured. Unpaired Student's t-test was used to analyze the results and a probability of p<0.05 was acceptable for rejection of the null hypothesis. The Pearson correlation was used to verify the association between the biomarkers analyzed in each group. Plasma levels of leptin (p = 0.0001), adiponectin (p = 0.0007) and BDNF (p = 0.003), and serum cortisol (p = 0.048) were significantly higher in overweight/obese infants than normal-weight infants. In contrast, the concentration of thiobarbituric acid reactive substances (TBARS) (p = 0.004), and catalase (p = 0.045) and superoxide dismutase activity (p = 0.02) were lower in overweight/obese infants than normal-weight peers. All the results together indicate neuroendocrine inflammatory response changes in overweight/obese infants between 6 and 24 months. Although there is already an environment that predisposes for a subsequent pro-inflammatory response, neuroendocrine secretion changes that permit the control of the inflammatory process in this age interval can be observed.

Evaluation of strength and irradiated movement pattern resulting from trunk motions of the proprioceptive neuromuscular facilitation.

Introduction. The proprioceptive neuromuscular facilitation (PNF) is a physiotherapeutic concept based on muscle and joint proprioceptive stimulation. Among its principles, the irradiation is the reaction of the distinct regional muscle contractions to the position of the application of the motions. Objective. To investigate the presence of irradiated dorsiflexion and plantar flexion and the existing strength generated by them during application of PNF trunk motions. Methods. The study was conducted with 30 sedentary and female volunteers, the PNF motions of trunk flexion, and extension with the foot (right and left) positioned in a developed equipment coupled to the load cell, which measured the strength irradiated in Newton. Results. Most of the volunteers irradiated dorsal flexion in the performance of the flexion and plantar flexion during the extension motion, both presenting an average force of 8.942 N and 10.193 N, respectively. Conclusion. The distal irradiation in lower limbs became evident, reinforcing the therapeutic actions to the PNF indirect muscular activation.

The effect of adding whole-body vibration to squat training on the functional performance and self-report of disease status in elderly patients with knee osteoarthritis: a randomized, controlled clinical study.

OBJECTIVES: The study objectives were to evaluate the effects of adding whole-body vibration to squat training on functional performance and self-report of disease in elderly individuals with knee osteoarthritis (OA). DESIGN: This was a prospective, randomized trial in which selected variables were evaluated at three periods: 3 weeks prior to the training, immediately prior, and after the end of the training. SUBJECTS: Twenty-three (23) elderly subjects were evaluated using four functional performance tests: Berg Balance Scale (BBS), Timed Get Up and Go Test (TGUG), Chair Stand Test (CST), and 6-Minute Walk Test (6MWT), and a self-report of the status of disease (WOMAC). INTERVENTIONS: The intervention lasted for 12 weeks, 3 times per week. The participants were randomized into two groups: (1) squat training with whole-body vibration, and (2) squat training without vibration. RESULTS: Although there was no statistical difference in functional performance and self-report of disease status between the groups, performance in all the functional tests and in all the domains of WOMAC improved in the vibration group compared to their initial status. In the exercise group, performance improved only two tests (BBS and 6MWT), and there was a reduction in self-reported pain (WOMAC) compared to their initial status. CONCLUSIONS: Although the addition of whole-body vibration to squat training failed to result in a significant improvement in functional performance and self-reported status of knee osteoarthritis in the elderly, the intragroup results suggest that whole-body vibration may represent a feasible and effective way of improving the functionality and self-perception of disease status in older adults with knee OA.