Maximizing acceleration and change of direction in sport

Compartimos la nueva publicación de nuestros compañeros de la Red Pleokinetic Andrés Baena, Manuel Rodríguez, Pedro Jiménez y Alberto Soriano del Laboratorio de la Universidad de Almería (España) en la revista Environmental Research and Public Health.

   

 Abstract

Sprint running and change of direction (COD) present similar mechanical demands, involving an acceleration phase in which athletes need to produce and apply substantial horizontal external force. Assessing the mechanical properties underpinning individual sprint acceleration might add relevant information about COD performance in addition to that obtained through sprint time alone. The present technical report uses a case series of three athletes with nearly identical 20 m sprint times but with different mechanical properties and COD performances. This makes it possible to illustrate, for the first time, a potential rationale for why the sprint force-velocity (FV) profile (i.e., theoretical maximal force (F0), velocity (V0), maximal power output (Pmax), ratio of effective horizontal component (RFpeak) and index of force application technique (DRF)) provides key information about COD performance (i.e., further to that derived from simple sprint time), which can be used to individualize training. This technical report provides practitioners with a justification to assess the FV profile in addition to sprint time when the aim is to enhance sprint acceleration and COD performance; practical interpretations and advice on how training interventions could be individualized based on the athletes’ differential sprint mechanical properties are also specified.

Keywords: acceleration; mechanical properties; explosive performance; assessment; team sports

Disponible en: https://www.mdpi.com/1660-4601/18/11/6140

 

Nueva publicación de nuestros compañeros y compañeras de la Red en la revista International Journal of Environmental Research and Public Health. En esta interesantísima investigación se compañran la situación física y mental la población de tres paises iberoamericanos como consecuencia de los confinamientos por el Covid-19. 

 

Abstract: 

Background: The aim of the present study was to determine the association between the health‐related quality of life (HRQoL) with sociodemographic parameters and lifestyle during COVID‐19 confinement in Mexico, Chile, and Spain. Methods: A cross‐sectional pilot study, with 742 observations of online surveys in 422, 190, and 130 individuals from Mexico, Chile, and Spain, respectively. Sociodemographic data, presence of comorbidities, food habits, and physical activity (PA) patterns were evaluated. The HRQoL was evaluated according to the SF‐36 Health Survey. The multilinear regression analysis was developed to determine the association of variables with HRQoL and its physical and mental health dimensions. Results: The female sex in the three countries reported negative association with HRQoL (Mexico: β −4.45, p = 0.004; Chile: β −8.48, p<0.001; Spain:  β  −6.22, p = 0.009). Similarly, bad eating habits were associated negatively with HRQoL (Mexico: β −6.64, p <0.001; Chile: β −6.66, p = 0.005; Spain: β −5.8, p = 0.032). In Mexico, PA limitations presented a negative association with HRQoL (β −4.71, p = 0.011). In Chile, a sedentary lifestyle (h/day) was linked negatively with HRQoL (β  −0.64, p = 0.005). In Spain, the highest associations with HRQoL were the presence of comorbidity (β −11.03, p <0.001) and smoking (β−6.72, p = 0.02). Moreover, the PA limitation in Mexico (β −5.67, p = 0.023) and Chile (β −9.26, p = 0.035) was linked negatively with mental health. Conclusions: The bad eating habits, PA limitations, female sex, comorbidity presence, and smoking were parameters linked negatively with HRQoL.

Keywords: lifestyle; mental health; physical activity; comorbidities

Defensa de tesis doctoral del Dr. Jesualdo Cuevas Aburto

El pasado 24 de marzo nuestro investigador de la Red Pleokinetic, Jesualdo Cuevas Aburto, defendió su tesis doctoral “Análisis de la velocidad del lanzamiento en balonmano: fiabilidad, marcador agudo de fatiga, su mejora a través de diferentes métodos de entrenamiento de fuerza. elaboración de una guía didáctica para su desarrollo" en el programa de Ciencias de la Educación de la Universidad de Granada dirigida por los Dres. Sres. Luis Javier Chirosa Ríos y Amador García Ramos.

 

Dr. Jesualdo Cuevas

 

  

El presidente del tribunal fue el Dr. Javier Rojas Ruíz, como secretaria Dra. Mar Cepero González (Universidad de Granada, España) y los vocales Dra. Fatima Chacón Borrego (Universidad de Sevilla, España), Dr. Manuel Rodríguez Pérez (Universidad de Almería, España) y el Dr. Daniel Jerez Mayorga (Universidad Andrés Bello, Chile).

La Tesis Doctoral buscaba abordar tres objetivos fundamentales en relación a la velocidad de lanzamiento: (I) identificar el procedimiento de evaluación que permita maximizar la fiabilidad en la medición de la velocidad de lanzamiento, (II) dilucidar si la velocidad de lanzamiento es una variable sensible a la fatiga inducida por sesiones de entrenamiento de fuerza que difieren en la configuración de la serie, y (III) comparar el efecto de varios programas de entrenamiento sobre la mejora de la velocidad de lanzamiento.

   

Presentación de la tesis en el acto de defensa

   

Los principales hallazgos de los estudios fueron: 1) la velocidad de lanzamiento puede ser evaluada con una fiabilidad muy alta en los participantes con y sin experiencia previa en la práctica del balonmano con la única excepción de un lanzamiento inespecífico en los participantes sin experiencia.;2) clúster y redistribución del descanso permite velocidades más altas durante el entrenamiento que una configuración de serie tradicional en los ejercicios de SQ y PB; 3) 4 semanas de programa de entrenamiento de fuerza basado exclusivamente en el ejercicio PB es capaz de afectar selectivamente parte superior del cuerpo y mejorar la fuerza máxima pero no la velocidad de lanzamiento; y 4) la velocidad de lanzamiento no estuvo asociada con el rendimiento en el ejercicio de PB realizado en máquina Smith.

Gender-specific association of the sprint mechanical with change direction in basketball

Compartimos la nueva publicación de nuestros compañeros de la red Andrés Baena, Pedro Jiménez, Enrique Salinas, Alberto Soriano y Manuel Rodríguez en la revista Journal of Strength and Conditioning Research sobre el cambio de dirección en baloncesto.

Abstract

We evaluated the gender-specific associations between the mechanical variables derived from the horizontal force-velocity (FV) profile (i.e., theoretical maximal force [F0], velocity [V0], maximal power output [Pmax], peak ratio of the effective horizontal component [RFpeak], and the force application technique index [DRF]) and the change of direction (COD) performance for basketball players. Seventy-one players (23 women and 48 men) were assessed for the horizontal FV profile and COD using the modified 505 and V-cut tests. The FV profile parameters were significantly higher for the men than those for the women. The F0, RFpeak, and Pmax were strongly associated with performance in the 505 test (women rrange = −0.72 to −0.82; men: rrange = −0.67 to −0.75; p < 0.001) and the V-cut test (women rrange = −0.68 to −0.76; men rrange = −0.45 to −0.50; p < 0.001), as well as with a lower COD deficit (women rrange = 0.58 to 0.75 (p < 0.01); men rrange = 0.49 to 0.54; all p < 0.001). For the women, a 1 N·kg−1 increase of the F0 was associated with −0.20 seconds and −0.56 seconds in the 505 and V-cut tests, respectively, and 0.16 seconds for the COD deficit. In the men, it was associated with −0.13 seconds and −0.37 seconds in the 505 and V-cut tests, respectively, and 0.10 seconds for the COD deficit. F0, RFpeak, and Pmax are the most determinant sprint mechanical properties to successfully COD and reduce the COD deficit. The horizontal FV profile assessment is recommended for diagnosing and prescribing a training program for basketball players.

Keywords

force , power , velocity , profile , acceleration

Disponible en:

https://journals.lww.com/nsca-jscr/Abstract/9000/Gender_Specific_Association_of_the_Sprint.94087.aspx

Isokinetic trunk strength in acute low back pain patients compared to healthy subjects: A systematic review

Nuestros compañeros de la Red Pleokinetic Waleska Reyes, Luis Chirosa, Angela Rodríguez, Daniel Jerez e Ignacio Chirosa han presentado una interesante revisión sistemática en la prestigiosa revista Environmental Research and Public Health sobre la fuerza en pacientes con dolor agudo de espalda.

   

      

Abstract 

Background: The purpose of this systematic review was to: (I) determine the quality of evidence from studies assessing trunk isokinetic strength in subjects with acute low back pain (ALBP) compared to healthy subjects and (II) establish reference values of isokinetic trunk strength in subjects with ALBP.  methodology: Preferred Reporting Items for Systematic Review and MetaAnalyses (PRISMA) statements were followed using keywords associated with trunk, strength and low back pain. Four databases were used: PubMed, Web of Science, Scopus and SPORTDiscus. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS). Results: A total of 1604 articles were retrieved, four included in this review. All were evaluated as high risk of bias (Rob). Due to the high Rob and the diversity of protocols, instruments and variables used, it was not possible to determine reference values for subjects with ALBP, we can only establish a range of flexion peak torque (PT) between 175.1 and 89.7 Nm at 60°/s and between 185 and 81.5 Nm at 120°/s, and for extension PT between 240.0 and 91.5 Nm at 60°/s and between 217.5 and 69.2 Nm at 120°/s in subjects with ALBP. Conclusions: Due to the low quality of the evidence and the diversity of protocols used when measuring trunk isokinetic strength, it is necessary to carry out new high-quality research to establish reference values of trunk strength in subjects with ALBP.

Keywords: dynamometer; core muscles; trunk strength testing; reference data; peak torque

Behavior of the muscle quality index and isometric strength in elderly women

Este estudio publicado en la revista Physiology & Behavior ha sido realizado por nuestro compañeros de la Red Pleokinetic Daniel Jerez, Pedro Delgado, Christian Campos, Juan García, Amador Garcia Ramos y Luis Javier Chirosa.

   

   

 
Abstract

This study aimed (I) to compare the muscle quality index (MQI) and the isometric hip strength between younger and older women, and (II) to determine the relationship of the MQI with the sit-to-stand test (STS) and isometric hip strength in younger and older women. Twenty-eight elderly women (age= 66.2 ± 5.6 years) and twenty younger women (21.2 ± 2.2 years) participated in the study. The following dependent variables were measured: MQI, STS, body composition, and the peak isometric strength of the hip (PF) which was also normalized using three different methods (PF/Body Mass, PF/Fat-Free Mass, and PF/Body Mass0,335). Older women presented a lower PF in hip flexion, extension and external rotation regardless of the method of normalization (p < 0.001), but the PF of hip abductors and internal rotators was higher for older women (p < 0.05). No significant differences were found in the MQI between older and younger women (p = 0.443). The MQI was negatively correlated with the time in the STS in older women (r = -0.706, p < 0.001) and younger women (r = -0.729, p < 0.001), while the correlations of MQI with isometric hip strength were weaker in older women (r range: -0.082 – 0.556) and younger women (r range: -0.020 – 0.309). MQI is a clinical and practical tool to assess the muscular power of the lower extremities.

Reliability of low-cost near-infrared spectroscopy in the determination of muscular oxygen saturation and hemoglobin concentration during rest, isometric and dynamic Strength Activity

Compartimos la publicación de nuestros compañeros de la Red Pleokinetic Claudia Miranda, Isabel Guisado, Pedro Delgado, Alejandro Pérez, Daniel Jerez y Luis Javier Chirosa titulado "Reliability of low-cost near-infrared spectroscopy in the determination of muscular oxygen saturation and hemoglobin concentration during rest, isometric and dynamic strength activity" en la revista Environmental Research and Public Health.

    

   

Abstract

Background: The objective of this study was to establish the reliability of the Humon Hex near-infrared reflectance spectroscopy (NIRS) in determining muscle oxygen saturation (SmO2) and hemoglobin concentration (Hgb) at rest and during isometric and dynamic strength exercises using a functional electromechanical dynamometer (FEMD). Methods: The SmO2 and Hgb values of sixteen healthy adults (mean ± standard deviation (SD): Age = 36.1 ± 6.4 years) were recorded at rest and during isometry (8 s), dynamic strength I (initial load of 40% of the average isometric load, with 2 kg increments until muscle failure) and dynamic strength II (same as I, but with an initial load of 40% of the maximum isometric load) activity. To evaluate the reliability in the determination of SmO2 and Hgb of this device, intraclass correlation coefficient (ICC), standard error of measurement (SEM) and coefficient of variation (CV) were obtained. Results: The main results obtained are SmO2 at rest (CV = 5.76%, SEM = 3.81, ICC = 0.90), isometric strength (CV = 3.03%, SEM = 2.08, ICC = 0.92), dynamic strength I (CV = 10.6, SEM = 7.17, ICC = 0.22) and dynamic strength II (CV = 9.69, SEM = 6.75, ICC = 0.32); Hgb at rest (CV = 1.97%, SEM = 0.24, ICC = 0.65), isometric strength (CV = 0.98%, SEM = 0.12, ICC = 0.96), dynamic strength I (CV = 3.25, SEM = 0.40, ICC = 0.54) and dynamic strength II (CV = 2.74, SEM = 0.34, ICC = 0.65). Conclusions: The study shows that Humon Hex is a reliable device to obtain SmO2 and Hgb data in healthy adult subjects at rest and during isometric strength, providing precision for measurements made with this device.

Keywords: strength training; dynamometer; tissue saturation; hemoglobin

Disponible en: https://www.mdpi.com/1660-4601/17/23/8824/htm