Dr. Ulloa-Diaz, David

Purpose: This study aimed to examine the reliability of trunk extensor strength assessment with a functional electromechanical dynamometer (FEMD). Methods: Thirty-one men performed strength assessment at different velocities (V) (V1 = 0.15 m·s−1, V2 = 0.30 m·s−1, V3 = 0.45 m·s−1) and range of movement (R) (R1 = 25% cm; R2 = 50% cm), and isometric contraction at 90º. Reliability was obtained through the intraclass correlation coefficient (ICC), typical error (TE), and coefficient of variation (CV). Results: The absolute reliability provided stable repeatability of the average eccentric strength in the V1R1 condition (CV = 9.52%) and the maximum eccentric strength in V1R1 (CV = 9.63%) and V2R2 (CV = 9.66%). The relative reliability of the trunk extensor’s average strength was good (ICC = 0.77–0.83) for concentric and good (ICC = 0.78–0.85) and moderate (ICC = 0.67–0.74) for eccentric contraction. Also, good (ICC = 0.77–0.81) and moderate (ICC = 0.55–0.74) reliability of the maximum strength were obtained for concentric and eccentric contraction. The most reliable manifestation to evaluate the concentric (CV = 11.33%) and eccentric (CV = 9.52%) strength was the average strength in the V1R1 condition and the maximum strength (CV = 10.29%) to isometric assessment. The average concentric strength in the V2R2 condition (r = 0.69) and the maximum eccentric strength in the V1R1 condition (r = 0.65) were the best related to the maximum isometric strength. Conclusions: FEMD is a highly reliable device to evaluate trunk extensors strength.

Background: The functional fitness of older people may be associated with their nutritional status. Aim: To assess the association between of anthropometric measures with functional fitness in older people. Material and Methods: Cross-sectional study conducted in 75 participants aged 65 to 89 years. Body mass index (BMI), waist-to-height ratio (WHtR), fat mass (FM) and skeletal muscle mass index (SMI) were calculated from anthropometric measures. The functional fitness was determined using the Senior Fitness Test battery. Results: BMI and FM indicated obesity, and WHtR indicated cardiometabolic risk in 49%, 55% and 83% of participants, respectively. SMI indicated a low muscle mass in 91% of females. Performance standards of chair stand, arm curl, 2-min step test and 8-foot up-and-go tests were met in 1%, 8%, 1% and 89% of participants, respectively. Significant negative correlations were found between 2-min step test and BMI, WHtR and FM (r = −0.26, −0.31 and −0.48 respectively). Back scratch had a negative correlation with BMI (r = −0.23) and SMI (rho = −0.28). Significant positive correlations were found between 8-foot up-and-go, WHtR (rho = 0.28) and FM (rho = 0.23), and between 2-min step test and SMI (rho = 0.28). The coefficient of determination (R2) between 2-min step test with BMI, WHtR and FM were 0.05, 0.08 and 0.22, respectively, while the R2 between back scratch and BMI was 0.04. Multiple regression models indicated that FM affected the 2-min step test independently of BMI and WHtR (adjusted R2 = 0.22), however age and sex negatively influenced these associations. Conclusions: Functional fitness of older adults is influenced by nutritional anthropometric measures, particularly BMI, WHtR and FM for aerobic capacity, and BMI for upper limb flexibility.

El objetivo de este estudio fue determinar el efecto de la técnica de secuencias de bracing en la estabilidad del core y el rendimiento en kata de karatecas. 38 deportistas masculinos de karate participaron en el estudio divididos en un grupo experimental (n=21) y un grupo de control (n=17). La prueba de rendimiento del deportista y la prueba de estabilidad del core se realizaron en pretest y postest posterior a 8 semanas de programa de estabilidad del core (técnica de secuencias de bracing). El grupo experimental mostró una mejora significativa en la prueba de rendimiento del atleta (p < 0,001) y en la prueba de estabilidad del core con (p < 0,05). Hubo una correlación positiva muy fuerte entre la prueba de rendimiento del atleta y el cinturón del karateca (ρ =0.780), una correlación positiva considerable entre la prueba de estabilidad del core y el cinturón del jugador (ρ =0.604), una correlación positiva considerable entre la prueba de rendimiento del atleta y la edad del jugador (ρ=0.554), y una correlación positiva media entre la prueba de estabilidad del core y la edad del jugador (ρ=0.481). En conclusión, los karatecas mostraron una gran mejora en el rendimiento del kata y en el nivel de estabilidad del core después del programa de técnicas de secuencias de bracing.

La percepción de la clase de educación física por parte de los estudiantes es un factor importante porque dependiendo de cómo los escolares perciban estas vivencias, se generarán determinadas creencias o valoraciones, las que influyen en la actitud para enfrentar estas experiencias corporales cada vez que se presenten. 176 estudiantes (14.74 ± 0.68), pertenecientes a los establecimientos particulares subvencionados de la comuna de Coronel. El objetivo de esta investigación es analizar la percepción actitudinal subjetiva de los estudiantes de enseñanza secundaria hacia los profesores de EF. Para evaluar la percepción actitudinal de los estudiantes hacia el profesor de educación física, se utilizó una modificación del cuestionario de actitudes de los escolares hacia la educación física. En los resultados de la actitudes positivas, se puede indicar que el alumnado valoro mayormente el ítem “Muy de acuerdo” en la pregunta “Mi profesor/a de educación física sabe mucho”, en las actitudes negativas la pregunta “Mi profesor/a de educación física levanta la voz frecuentemente” fue el mayor porcentaje en el ítem “Muy de acuerdo” . En el análisis comparativo entre hombres y mujeres para la percepción positiva reporto (p = 0.63) y negativa (p = 0.10). En el análisis por edades para la escala positiva (p = 0.01), para la escala negativa (p = 0.25). El alumnado observo mayormente actitudes positivas de y muy pocas negativas en el profesor de educación física, sin observase diferencias entre hombres y mujeres, en las edades se reportaron diferencias en las actitudes positivas y negativas del profesor, informando que los alumnos de con más edad evalúan más críticamente las actitudes positivas y negativas del profesor de EF.

Introduction: the regular practice of physical exercise is an important modulator of resting energy expenditure (REE), which depending on the intensity, duration, and type of exercise can increase the REE in an acute manner as well as long term. The effects of dynamic muscular strength exercises on the REE have been treated very little in literature. Objective: compare the effect of muscle strength exercise (MSE) at different intensities on the REE in young males. Methods: Intra-group design. Fourteen subjects aged 22,5±1,5 0,05) after the exercise at 40%RM. The REEpost 24h was maintained according to the REEpre when the intensity was 80%RM. Conclusion: The REEpost exercise is independent of the intensity of the exercise and only is maintained after 24 hours when the MSE is at a high intensity

The purpose of the study was to analyze the test–retest reliability of an isometric and isometric/vibratory muscular strength protocol in the bilateral seated bench press (BSBP), bilateral seated rowing (BSR), unilateral seated right knee extension (USKER), and left knee extension (USKEL) tests controlled using functional electromechanical dynamometry (FEMD) in healthy young adults. A repeated measures design was used to determine the reliability of a muscular strength protocol in isometric and isometric vibration modes with FEMD. No significant differences were found in test–retest analysis (p > 0.05; ES < 0.20); and high reliability (CV = 4.65–5.02%; ICC = 0.99–0.98) was found for BSBP measures, and acceptable reliability (CV = 3.71–9.61%; ICC = 0.98–0.95) was found for BSR, USKER, and USKEL. Furthermore, the coefficients between the two measures were strong (r = 0.963–0.839) and highly significant (p = 0.001) for maximal strength in the isometric and maximal isometric/vibratory assessment of muscle strength in all muscle strength tests. This study demonstrates that isometric and maximal isometric/vibratory strength in the BSBP, BSR, USKER, and USKEL tests can be measured with high reliability and reproducibility using the FEMD.

This aims of this study were (I) to determine the velocity variable and regression model which best fit the load-velocity relationship during the free-weight prone bench pull exercise, (II) to compare the reliability of the velocity attained at each percentage of the one-repetition maximum (1RM) between different velocity variables and regression models, and (III) to compare the within- and between-subject variability of the velocity attained at each %1RM. Eighteen men (14 rowers and four weightlifters) performed an incremental test during the free-weight prone bench pull exercise in two different sessions. General and individual load-velocity relationships were modelled through three velocity variables (mean velocity [MV], mean propulsive velocity [MPV] and peak velocity [PV]) and two regression models (linear and second-order polynomial). The main findings revealed that (I) the general (Pearson’s correlation coefficient [r] range = 0.964–0.973) and individual (median r = 0.986 for MV, 0.989 for MPV, and 0.984 for PV) load-velocity relationships were highly linear, (II) the reliability of the velocity attained at each %1RM did not meaningfully differ between the velocity variables (coefficient of variation [CV] range = 2.55–7.61% for MV, 2.84–7.72% for MPV and 3.50–6.03% for PV) neither between the regression models (CV range = 2.55–7.72% and 2.73–5.25% for the linear and polynomial regressions, respectively), and (III) the within-subject variability of the velocity attained at each %1RM was lower than the between-subject variability for the light-moderate loads. No meaningful differences between the within- and between-subject CVs were observed for the MV of the 1RM trial (6.02% vs. 6.60%; CV ratio = 1.10), while the within-subject CV was lower for PV (6.36% vs. 7.56%; CV ratio = 1.19). These results suggest that the individual load-MV relationship should be determined with a linear regression model to obtain the most accurate prescription of the relative load during the free-weight prone bench pull exercise.

Background: There is no conclusive evidence about the association between physical fitness (PF) and health related quality of life (HRQOL) in older adults. Aim: To seek for an association between PF and HRQOL in non-disabled community-dwelling Chilean older adults. Material and Methods: One hundred and sixteen subjects participated in the study. PF was assessed using the Senior Fitness Test (SFT) and hand grip strength (HGS). HRQOL was assessed using eight dimensions provided by the SF-12v2 questionnaire. Binary multivariate logistic regression models were carried out considering the potential influence of confounder variables. Results: Non-adjusted models, indicated that subjects with better performance in arm curl test (ACT) were more likely to score higher on vitality dimension (OR > 1) and those with higher HGS were more likely to score higher on physical functioning, bodily pain, vitality and mental health (OR > 1). The adjusted models consistently showed that ACT and HGS predicted a favorable perception of vitality and mental health dimensions respectively (OR > 1). Conclusions: HGS and ACT have a predictive value for certain dimensions of HRQOL.

Introducción: El ejercicio físico es un importante modulador de la máxima tasa de oxidación de grasas (MFO). Sin embargo, en la relación MFO-ejercicio, las zonas de transición metabólica en la prescripción del ejercicio no son consideradas. Objetivo: Conocer el efecto del entrenamiento en diferentes zonas de transición metabólica sobre la cinética de la MFO y su localización (Fatmax) en jóvenes varones activos. Método: 97 varones fueron distribuidos en 4 grupos homogéneos, 3 experimentales y un grupo control (GC). Cada grupo experimental participó en 8 semanas de entrenamiento administrado de forma continua a intensidad de umbral aeróbico o VT1 (CCVT1), interválica en umbral anaeróbico o VT2 (ITVT2), y en potencia aeróbica máxima o VO2max (ITVO2max). Antes y después del tratamiento los sujetos fueron testados en sendas pruebas con control de gases espirados para determinar el VO2max, VT1 y VT2, y la MFO (calorimetría indirecta) y Fatmax. Resultados: Los resultados muestran un incremento (entre 16,49 y 18,51%; p<0,01) en la MFO en los grupos experimentales. La Fatmax se redujo de media del 60,72±10,52 al 52,35±7,61 %VO2max (p<0,01) por efecto del entrenamiento. El grupo control no experimentó cambios de interés. El análisis intergrupo no presentó diferencias entre los grupos experimentales en ambas variables, sin embargo la comparación contra el GC, reflejó un mayor descenso de la Fatmax en CCVT1 (p<0,05). No se registraron cambios en el rendimiento, salvo un descenso del VO2max en el GC (p<0,05). Conclusión: 8 semanas de entrenamiento de diferente intensidad incrementan la MFO y reducen la Fatmax.

El estudio tiene como propósito analizar la fiabilidad de la prueba de 8 lanzamientos de 3 diferentes variantes de lanzamientos de balonmano en estudiantado universitario. 33 varones, 20 ±1,9 años peso 72,39±8,9 kg altura 176,75 ±6,07 cm IMC 23,14±2,3. Los sujetos participantes fueron evaluados en 2 sesiones separadas entre sí por un lapso de una semana. Ejecutaron lanzamientos hasta quedar registrados 8 mediciones en cada una de las pruebas, lanzamientos inespecíficos, en apoyo y en carrera con 3 pasos, se registró la velocidad de lanzamiento con un radar posterior a la portería. La fiabilidad del promedio de las puntuaciones del test de 8 medidas entre la primera sesión y la segunda con una prueba test-retest, se obtuvieron los siguientes resultados: en el lanzamiento inespecífico se obtuvo un ICC= (0,86) entre el 95% de confianza, un de CV= (7,43%) y un ES= (0,08). Para el lanzamiento con apoyo se obtuvo un ICC= (0,94) al 95 % de confianza, un de CV= (4,71 %) y un ES= (-0,09). Para el lanzamiento con carrera se obtuvo un ICC= (0,96) al 95 % de confianza, un de CV= (4,00 %) y un ES= (0,05). Este estudio ha demostrado que la prueba de 8 lanzamientos y las 3 variantes es una medida de rendimiento confiable y estable para estudiantes de nivel universitario sin experiencia en el balonmano, en relación con las variables del lanzamiento, las 3 fueron fiables, solo la variable inespecífica fue menor en comparación al lanzamiento con apoyo y con carrera.