Factors influencing exercise tolerance after stroke / 中华物理医学与康复杂志

Objective:To observe the recovery of exercise tolerance among stroke survivors using the cardiopulmonary exercise test (CPET) and analyze the factors influencing it.Methods:A total of 81 stroke survivors hospitalized in the Department of Rehabilitation Medicine of our hospital in year 2018 and 2019 were selected. The general clinical data of all patients were collected retrospectively and combined with the data from CPET to establish a data set. Version 25.0 of the SPSS software was used for multiple linear regressions analysis, with the peak oxygen uptake as the dependent variable, and the age, Brunnstrom stage, peak power, peak heart rate, peak respiratory exchange ratio, peak breathing reserve, peak ventilation per minute, the slope of the VE-VCO 2 curve (ΔVE/ΔVCO 2) and peak end tidal partial pressure of carbon dioxide as independent variables. Results:Stroke survivors at Brunnstrom stage III Ⅲ, Ⅳ and Ⅴ or higher decreased sequentially with their age, but their peak oxygen uptake increased gradually. The multiple linear regression model constructed by " stepwise method" showed that the fitted multiple linear regression equation was statistically significant ( F=100.228, P<0.001). Moreover, the average peak power, peak heart rate, peak ventilation per minute and the slope of the VE-VCO 2 curve were all found to be significant independent predictors of peak oxygen uptake in these stroke survivors. Conclusions:Skeletal muscle power, cardiac function, pulmonary ventilation and ventilation efficiency are useful independent predictors of the exercise tolerance of stroke survivors.

Validation of the ST3x1 Step Test as an estimator of peak VO2 in adults with cardiovascular risk factors / Validación del Test de Escalón ST3x1 como estimador del VO2 pico en adultos con factores de riesgo cardiovascular

Abstract Objective: To validate a tool for assessment and control of functional capacity and peak oxygen uptake. Methods: A transversal, correlational study was conducted in which 111 subjects (49.81 ± 11.16 years) were evaluated, their body mass index (BMI) was 31.42 ± 4.07, classified with moderate and high cardiovascular risk, according to the American Association of Cardiovascular and Pulmonary Rehabilitation. Its peak oxygen uptake was measured directly and also through the Step Test 3x1 (ST3x1). Results: Peak oxygen uptake in ST3x1 corresponded to 28.54 ml•kg-1•min-1 and direct measurement at 28.14 ml•kg-1•min-1, with a "strong positive" Pearson correlation r = 0.81, Student n/s p = 0.14 Conclusion: ST3x1 is a valid alternative to estimate peak oxygen uptake in the group studied, and can be used in mass public health physical activity programs.

Resumen Objetivo: Validar una herramienta de estimación y control de la capacidad funcional y el consumo de oxígeno pico. Materiales y métodos: Se realizó un estudio transversal, correlacional donde se evaluaron a 111 sujetos (49.81 ± 11.16 años), su índice de masa corporal (IMC) fue de 31.42 ± 4.07, clasificados con riesgo cardiovascular mediano y alto, según la American Association of Cardiovascular and Pulmonary Rehabilitation. Se midió su consumo pico de oxígeno en forma directa y también a través del Step Test 3x1 (ST3x1). Resultados: El consumo de oxígeno pico en ST3x1 correspondió a 28.54 mlŸkg -1 Ÿmin -1 y en la medición directa a 28.14 mlŸkg -1 Ÿmin -1, con una correlación de Pearson fuerte positiva r = 0.81, Student n/s p = 0.14. Conclusión: ST3x1 se presenta como alternativa para estimar el consumo de oxígeno pico en el grupo estudiado, pudiendo ser usado en programas masivos de actividad física en salud pública.

Fat mass is negatively associated with the physiological ability of tissue to consume oxygen

To describe the relationship between variables related to body composition and peak oxygen uptake ( V˙O2 peak) and to verify whether fat mass can affect these relationships. Methods: Eighty participants underwent cardiopulmonary exercise testing to measure V˙O2 peak and a body composition assessment to measure fat mass, fat free mass (FFM), and total body mass (BM). Results: There were significant relationships between V˙O2 peak relative to FFM (fat free mass) (mL/kgFFM/min) and absolute fat mass (kg) (r=-0.50, p<0.001) and relative fat mass (%) (r=-0.56, p<0.001). Absolute V˙O2 peak (L/min) had a high positive relationship with FFM (r=0.83, p<0.0001); the relationship between V˙O2 peak (L/min) and FFM remained high and positive even when accounting for absolute fat mass (kg) (r=0.83, p<0.001). V˙O2 peak relative to total body mass (mL/kgBM/min) showed a high negative relationship with relative fat mass (%) (r=-0.89, p<0.001) and a positive relationship with fat free mass (kg) (r=0.57, p<0.001), which did not change when accounting for fat mass (kg) (r=0.56, p<0.001). Conclusion: These data indicate that the physiological ability of tissue to consume oxygen ( V˙O2 peak in mL/kgFFM/min) is negatively associated with fat mass. Moreover, the individual's cardiorespiratory capacity to transport oxygen for working muscles ( V˙O2 peak in L/min) is strongly related to absolute FFM, and this association is not affected by fat mass. Finally, a better body mass composition (high FFM and low fat mass) is important for aerobic physical fitness ( V˙O2 peak in mL/kgBM/min) and improved physiological ability of tissue to consume oxygen ( V˙O2 peak in mL/kgFFM/min).(AU)

Validación del test de 6 minutos de carrera como predictor del consumo máximo de oxígeno en el personal naval / Validation of the 6-minute race test as a predictor of maximum oxygen consumption in naval personnel

Introducción: las altas demandas físicas requeridas para el desarrollo de las tareas propias del personal naval, exige un alto desarrollo del consumo máximo de oxígeno (VO2max) en dicha población. Encontrar pruebas que midan el VO2max en el personal naval de forma confiable y válida, además de que sean de fácil aplicación y con poca infraestructura es una labor pendiente. Objetivo: validar el test de 6 minutos de carrera (t-6 min) en el personal naval. Métodos: estudio correlacional, con una muestra de 224 cadetes de la Escuela Naval pertenecientes a la Armada de Chile. Las variables medidas fueron: VO 2max y distancia evaluada a través del t-6 min y el test de 12 minutos (t-12 min). Para el análisis estadístico se utilizó una correlación de Pearson y la técnica Bland-Altman. En el análisis Post hoc se utilizó la prueba t de Student, mientras el tamaño del efecto (TE) fue calculado con una d de Cohen. Resultados: la correlación del VO2max estimado entre el t-6 min y el t-12 min fue de 0,60. El análisis Post hoc mostró diferencias significativas en el VO2max estimado de ambas pruebas de campo (p < 0,0001; TE = 1,016). En el análisis de Bland-Altman se observó la relación entre los valores medios y las diferencias del VO2max estimado entre el t-12 min y el t-6 min, estuvieron en torno a -3,03. Conclusión: los resultados del estudio mostraron una correlación buena entre el t-6 min y el t-12 min. Por tal razón, el t-6 min es una prueba válida para ser aplicada en el personal naval(AU)

Introduction: The high physical demands that Navy personnel face in order to perform their day-to-day tasks entail a high development in peak oxygen uptake (VO 2max). Therefore, finding tests to measure VO2max in Navy personnel in a reliable and valid fashion requiring minor infrastructure and are easily performed is a pending matter. Objective: To validate a 6- minute run test (6WRT) in Navy personnel. Methods: correlational study, while the sample were 224 cadets of the Chilean Navy School. The variables to be measured were: VO2max and distance measured through a 6WRT and 12- minute test (12- min test). The statistical analysis was performed through the Pearson correlation test and the Bland-Altman technique. The post hoc analysis was performed with Student's t test and the size of the effect (SE) was measured using Cohen's d test. Results: The connection of the estimated VO2max between 6WRT and 12- min test was 0.06. The Post hoc analysis showed a significant difference between the estimated VO2max of both field tests (p < 0.0001; SE = 1.016). The Bland-Altman analysis evidenced a relation between media values and the differences of VO2max between 12- min test and 6WRT were approximately -3.03. Conclusion: The results of the study showed a positive connection between 6WRT test and 12- min test. Consequently, 6WRT test is a valid test to be applied in Navy personnel(AU)

Relationships between running performance and the cross–sectional area of the psoas major, and peak oxygen uptake in elite junior long–distance runners / 体力科学

The purpose of this study was to examine the relationships between running performance and the cross–sectional area of the psoas major, peak oxygen uptake, and running economy in male junior long–distance runners. The subjects were 37 male junior athletes who achieved good records in interscholastic athletic competition during 5 years (2011–2015). Their seasonal best times in a 5,000 m race (5,000m–SB) were 14:04.11 ± 0:07.25 (13:53.64–14:16.15). In a multiple regression analysis, 5,000m–SB was statistical significantly correlated with the cross–sectional area of psoas major (16.0 ± 1.7 cm²) measured on magnetic resonance imaging and peak oxygen uptake (4.25 ± 0.36 l min^-1 [76.9 ± 5.8 ml min^-1 kg^-1]) during a lactate curve test comprising five stages. However, 5,000m–SB was not related to oxygen uptake at the work–load which was less than the load at the lactate threshold estimated by using the lactate curve test results. These results suggest that a high volume of the psoas major, the largest hip–flexor muscle, and peak oxygen uptake are among the important factors for junior long–distance runner performance.

Características aeróbias e anaeróbias de mesatenistas brasileiros treinados / Aerobic and anaerobic characteristics of Brazilian trained table tennis players

O objetivo deste estudo foi determinar, em mesatenistas bem treinados, as aptidões aeróbia e anaeróbia. Participaram do presente estudo oito mesatenistas brasileiros treinados do sexo masculino (18±2 anos). Os sujeitos foram submetidos a um teste incremental específico para determinação do consumo pico de oxigênio (VO2PICO), intensidade associada ao VO2PICO(iVO2PICO) e do ponto de compensação respiratório (PCR) e a dois testes de esforço repetitivo, sendo o teste de RAST e o índice anaeróbio alático (IAA), para determinação dos índices anaeróbios. O VO2PICO correspondeu a 50,5±4,4ml kg-1 min-1, a VO2PICO a 52,1±9,6 bolas min-1 e o PCR a 44,9±8,0 bolas min-1. No RAST, a potência pico (PP) e a potência média (PM) relativa corresponderam a 9,0±1,3W kg-1 e 7,0±0,9W kg-1, respectivamente, enquanto que o IAA foi 1,14±0,51 mM/m s-1. Esses valores de VO2PICO e dos parâmetros anaeróbios quando comparados a valores de outros esportes com raquetes caracterizaram que mesatenistas brasileiros treinados apresentam potência aeróbia moderada e potência anaeróbia é baixa.

The purposes of this study were to determine the aerobic conditioning and anaerobic conditioning in trained table tennis players. Eigth Brazilian male table tennis players (18±2 years) participated of the study. Subjects performed graded exercise test in specific procedure to measure peak oxygen uptake (VO2peak), intensity associated at VO2PEAK (iVO2PEAK) and respiratoty conpensation point (RCP), and two repeated-sprint abilit tests (i.e., RAST and alactic anaerobic índex (AAI)), which were considered as anaerobic parameters. VO2PEAK corresponded to 50.5±4.4ml kg-1 min-1 , iVO2PEAK to 52.1±9.6balls min-1 e o RCP 44.9±8.0balls min-1. Peak power (PP) and mean power (MP) relative to body mass (PPr and MPr, respectively) measured during RAST were 9.0±1.3W kg-1 and 7.0±0.9W kg-1, respectively, whereas AAI (i.e., ratio of blood lactate and average speed) was 1.14±0.51mM/m s-1. Thus, we can conclude that trained Brazilian table tennis players have moderated aerobic power, low anaerobic conditioning.

Predicting Oxygen Uptake for Men with Moderate to Severe Chronic Obstructive Pulmonary Disease / 결핵및호흡기질환

BACKGROUND: Measurement of the maximum oxygen uptake in patients with chronic obstructive pulmonary disease (COPD) has been used to determine the intensity of exercise and to estimate the patient's response to treatment during pulmonary rehabilitation. However, cardiopulmonary exercise testing is not widely available in Korea. The 6-minute walk test (6MWT) is a simple method of measuring the exercise capacity of a patient. It also provides high reliability data and it reflects the fluctuation in one's exercise capacity relatively well with using the standardized protocol. The prime objective of the present study is to develop a regression equation for estimating the peak oxygen uptake (VO2) for men with moderate to very severe COPD from the results of a 6MWT. METHODS: A total of 33 male patients with moderate to very severe COPD agreed to participate in this study. Pulmonary function testing, cardiopulmonary exercise testing and a 6MWT were performed on their first visits. The index of work (6Mwork, 6-minute walk distance [6MWD]xbody weight) was calculated for each patient. Those variables that were closely related to the peak VO2 were identified through correlation analysis. With including such variables, the equation to predict the peak VO2 was generated by the multiple linear regression method. RESULTS: The peak VO2 averaged 1,015+/-392 ml/min, and the mean 6MWD was 516+/-195 meters. The 6Mwork (r=.597) was better correlated to the peak VO2 than the 6MWD (r=.415). The other variables highly correlated with the peak VO2 were the FEV1 (r=.742), DLco (r=.734) and FVC (r=.679). The derived prediction equation was VO2 (ml/min)=(274.306xFEV1)+(36.242xDLco)+(0.007x6Mwork)-84.867. CONCLUSION: Under the circumstances when measurement of the peak VO2 is not possible, we consider the 6MWT to be a simple alternative to measuring the peak VO2. Of course, it is necessary to perform a trial on much larger scale to validate our prediction equation.

Correlação entre a distância obtida no teste de caminhada de seis minutos e o pico de consumo de oxigênio em pacientes portadores de doença renal crônica em hemodiálise / Correlation between the distance covered in the six-minute walk test with peak oxygen uptake in end-stage renal disease patients on hemodialysis

Introdução: A doença renal crônica (DRC) cursa com importante redução da capacidade funcional. O teste padrão ouro para avaliação da capacidade funcional é o teste cardiopulmonar que determina o pico de consumo de oxigênio (VO2 pico). Por outro lado, o teste de caminhada de seis minutos (TC6M) é um teste representativo das atividades da vida diária, é mais barato e de fácil aplicação. No presente estudo, avaliamos a correlação entre a distância obtida no TC6M e o VO2 pico em pacientes portadores de DRC sob tratamento hemodialítico. Métodos: Foram estudados 16 pacientes portadores de DRC em programa de hemodiálise (cinco homens e 11 mulheres), com média de idade de 47,75 ± 12,05 anos. Os pacientes foram submetidos a dois TC6M emuma pista plana de 30m, com intervalo de 30 minutos, sendo considerada para análise a maior distância percorrida. Para determinação do VO2 pico, ospacientes foram submetidos ao teste cardiopulmonar em esteira rolante. Resultados: A distância média obtida no TC6M foi de 516,0 ± 88,79m e o VO2pico foi 20,50 ± 4,92ml/kg/min. Observamos uma correlação positiva e estatisticamente significante entre a distância obtida no TC6M e o VO2 pico (r =0,78). Conclusão: A forte correlação entre a distância obtida no TC6M e o VO2 pico permite sugerir o TC6M como alternativa simples e barata para avaliação da capacidade funcional de pacientes portadores de DRC em tratamento hemodialítico.

Introduction: End-stage renal disease (ESRD) courses with significant reduction in the functional capacity. The gold standard test for evaluation of the functional capacity is the cardiopulmonary test, which provides the determination of the peak oxygen uptake (VO2 peak). On the other hand, the six-minute walk test (6MWT) is a representative test of the daily living activities, is inexpensive and easily applicable. In this study we aimed to evaluate the correlation between the distance covered in 6MWT with VO2 peak in ESRD patients on hemodialysis. Methods: Sixteen ESRD patients on hemodialysis (five men and11 women) were studied, with a mean age of 47.75 ± 12.05 years. The patients were submitted to two 6MWT in a 30m corridor, with an interval of 30minutes, being considered for analysis longest walked distance. For determination of VO2 peak, the patients were submitted to the cardiopulmonary test on a treadmill. Results: The distance covered in 6MWT was 516.0 ± 88.79m and VO2 peak was 20.50 ± 4.92ml/kg/min. We observed a positive and significant correlation between the distance covered in 6MWT with VO2 peak (r =0.78). Conclusion: The strong correlation between the distance covered in 6MWT with VO2 peak allows us to suggest the 6MWT as a simple and cheap alternative for evaluation of the functional capacity in ESRD patients on hemodialysis.