Reliability and measurement error of tensiomyography to assess mechanical muscle function: A systematic review

Interest in studying mechanical skeletal muscle function through tensiomyography (TMG) has increased in recent years. This systematic review aimed to (a) report the reliability and measurement error of all TMG parameters [i.e., maximum radial displacement of the muscle belly (Dm), contraction time (Tc), delay time (Td), half-relaxation time (1/2 Tr), and sustained contraction time (Ts)] and (b) to provide critical reflection on how to perform accurate and appropriate measurements for informing clinicians, exercise professionals, and researchers. A comprehensive literature search was performed of the Pubmed, Scopus, Science Direct and Cochrane databases up to July 2017. Eight studies were included in this systematic review. Meta-analysis could not be carried out due to the low quality of the evidence of some studies evaluated. Overall, the review of the nine studies involving 158 participants revealed high relative reliability [intra-class correlation (ICC)] for Dm (0.91-0.99); moderate to high ICC for Ts (0.80-0.96), Tc (0.70-0.98), and 1/2 Tr (0.77-0.93); and low to high ICC for Td (0.60-0.98), independently of the evaluated muscles. Additionally, absolute reliability [coefficient of variation (CV)] was low for all TMG parameters except for 1/2 Tr (CV = >20%) while measurement error indexes were high for this parameter. In conclusion, this study indicates that three of the TMG parameters (Dm, Td and Tc) are highly reliable, whereas 1/2 Tr demonstrate insufficient reliability, and thus should not be used in future studies

Adicción al ejercicio en ciclistas

A pesar de que existe múltiple evidencia científica acerca de los beneficios del ejercicio físico sobre la salud física y mental, se ha sugerido que puede existir un límite en el volumen de ejercicio que puede ser perjudicial para la salud y crear un riesgo de adicción al ejercicio (RAE). La adicción al ejercicio (AE) ha sido descrita como un patrón mórbido de comportamiento en el que el individuo que se ejercita pierde el control sobre sus hábitos de ejercicio, exhibe dependencia y experimenta consecuencias negativas para la salud, así como en su vida social y profesional. El campo de la AE es relativamente nuevo y los resultados y conclusiones no estan claros. Una limitación significativa es el uso de múltiples terminologías para describir el mismo fenómeno (dependencia al ejercicio, ejercicio compulsivo, etc.). La investigación se basa principalmente en autoinformes obtenidos a partir de cuestionarios, como el Exercise Addiction Inventory (EAI), el cual evalúa el RAE, ya que este término incluye tanto la dependencia como la compulsión. La AE se sitúa dentro del campo de las adicciones conductuales, pero debido a la falta de evidencia sólida y metodológicamente rigurosa sobre la AE como una morbilidad, el trastorno no aparece como una disfunción mental en la última (quinta) edición del Manual Diagnóstico y Estadístico de los Trastornos Mentales (DSM-5). Existe una gran variabilidad entre estudios sobre la prevalencia de RAE. Aunque la prevalencia de REA establecida por el EAI obtenida en un estudio en población deportista general fue 3.2%, otros estudios muestran valores mucho más altos en atletas de resistencia (triatletas, corredores, etc.). El volumen excesivo de entrenamiento ha sido destacado como uno de los factores que podrían explicar esta variabilidad. A pesar de que el ciclismo es uno de los deportes de resistencia más comunes y practicados y esta asociado con una reducción de mortalidad por todas las causas, hasta la fecha, la literatura no ha valorado el REA en la población ciclista amateur y su asociación con la salud psicosocial (calidad de vida, calidad de sueño, ansiedad, etc.). Por lo tanto, el objetivo de este estudio fue obtener la prevalencia de RAE en una muestra de ciclistas amateur, analizar su asociación con factores de riesgo y, valorar su influencia en parámetros asociados con la salud física y mental de ciclistas.ConclusionesLa prevalencia del REA en los ciclistas amateur es del 17%. La práctica del ciclismo de resistencia amateur tiene efectos beneficiosos para la salud. Los beneficios en la calidad del sueño y la salud mental están limitados en aproximadamente el 20% de sujetos con RAE. Nuestros resultados también sugieren que el RAE en ciclistas de resistencia amateur no se ve significativamente influenciado por factores extrínsecos como edad, sexo, factores sociodemográficos y entrenamiento, lo que sugiere que para diagnosticar con precisión y establecer el tratamiento apropiado, psicólogos deportivos clínicos deben centrar su atención en los factores intrínsecos en cada sujeto que puede inducir la AE.<br /

Optimizing Field Body Fat Percentage Assessment in Professional Soccer Players

Body composition is a determinant of performance in soccer. To estimate the body fat percentage (%BF), dual energy X-ray absorptiometry (DXA) is effective though this method is expensive and not readily accessible. This study examines the validity of widely used field methods based on anthropometric data and bioelectrical impedance analysis (BIA). Participants were 21 male Spanish First Division soccer players aged between 22 and 35 years. In each participant, body fat mass was determined by BIA and using 18 anthropometric equations including skinfold (SKF) measurements. DXA was used as reference. Correlation with DXA measurements was excellent for all equations and separate SKF measurements yet only moderate for BIA. However, only the equation recently developed for use in soccer players based on iliac crest and triceps SKFs showed no significant or standardized differences with DXA-derived %BF and these measurements also had the lowest bias. Our findings suggest that when DXA is not available, the best field method for %BF assessment in footballers is the equation based on iliac crest and triceps SKF. As another good option, we propose the sum of triceps, subscapular, supraspinal, and abdominal SKFs, as this combination also showed good correlation with DXA

Land- and water-based exercise intervention in women with fibromyalgia: the al-andalus physical activity randomised controlled trial

Background The al-Andalus physical activity intervention study is a randomised control trial to investigate the effectiveness of a land- and water-based exercise intervention for reducing the overall impact of fibromyalgia (primary outcome), and for improving tenderness and pain-related measures, body composition, functional capacity, physical activity and sedentary behaviour, fatigue, sleep quality, health-related quality of life, and cognitive function (secondary outcomes) in women with fibromyalgia. Methods/Design One hundred eighty women with fibromyalgia (age range: 35-65 years) will be recruited from local associations of fibromyalgia patients in Andalucía (Southern Spain). Patients will be randomly assigned to a usual care (control) group (n = 60), a water-based exercise intervention group (n = 60) or a land-based exercise intervention group (n = 60). Participants in the usual care group will receive general physical activity guidelines and participants allocated in the intervention groups will attend three non-consecutive training sessions (60 min each) per week during 24 weeks. Both exercise interventions will consist of aerobic, muscular strength and flexibility exercises. We will also study the effect of a detraining period (i.e., 12 weeks with no exercise intervention) on the studied variables. Discussion Our study attempts to reduce the impact of fibromyalgia and improve patients' health status by implementing two types of exercise interventions. Results from this study will help to assess the efficacy of exercise interventions for the treatment of fibromyalgia. If the interventions would be effective, this study will provide low-cost and feasible alternatives for health professionals in the management of fibromyalgia. Results from the al-Andalus physical activity intervention will help to better understand the potential of regular physical activity for improving the well-being of women with fibromyalgia.This study was supported by the Consejeria de Turismo, Comercio y Deporte (CTCD-201000019242-TRA), the Spanish Ministry of Science and Innovation (I + D + I DEP2010-15639, grants: BES-2009-013442, BES-2011-047133, RYC-2010-05957, RYC-2011-09011), the Swedish Heart-Lung Foundation (20090635), the Spanish Ministry of Education (AP-2009-3173), Granada Research of Excelence Initiative on Biohealth (GREIB), Campus BioTic, University of Granada, Spain and European University of Madrid. Escuela de Estudios Universitarios Real Madrid. 2010/04RM

Average VO2max as a function of running performances on different distances

Détermination des valeurs moyennes et des différences de VO2max pour des coureurs hommes et femmes de différents niveaux de performance (pointage IAAF) du 100 m au 42,2 k

Optimizing Field Body Fat Percentage Assessment in Professional Soccer Players

Body composition is a determinant of performance in soccer. To estimate the body fat percentage (%BF), dual energy X-ray absorptiometry (DXA) is effective though this method is expensive and not readily accessible. This study examines the validity of widely used field methods based on anthropometric data and bioelectrical impedance analysis (BIA). Participants were 21 male Spanish First Division soccer players aged between 22 and 35 years. In each participant, body fat mass was determined by BIA and using 18 anthropometric equations including skinfold (SKF) measurements. DXA was used as reference. Correlation with DXA measurements was excellent for all equations and separate SKF measurements yet only moderate for BIA. However, only the equation recently developed for use in soccer players based on iliac crest and triceps SKFs showed no significant or standardized differences with DXA-derived %BF and these measurements also had the lowest bias. Our findings suggest that when DXA is not available, the best field method for %BF assessment in footballers is the equation based on iliac crest and triceps SKF. As another good option, we propose the sum of triceps, subscapular, supraspinal, and abdominal SKFs, as this combination also showed good correlation with DXA