157 research outputs found
Efectos y adaptaciones de diferentes modalidades de entrenamiento resistido sobre el rendimiento en jugadores de fútbol.
El fútbol es un deporte de equipo en el que el rendimiento depende tanto de las habilidades individuales como de la interacción colectiva entre los jugadores. Por ello, las habilidades tácticas y técnicas son consideradas los principales factores que influyen en el resultado final de un partido. Sin embargo, el desarrollo de las capacidades físicas no debe pasarse por alto a la hora de desarrollar jugadores de alto nivel. Concretamente, acciones de alta intensidad como el esprint, el cambio de dirección y el salto han sido relacionadas positivamente con el rendimiento en el fútbol y, además, son las acciones de alta intensidad más comunes en las situaciones de gol. El éxito en estas acciones se ha relacionado con la capacidad del atleta para maximizar la producción de potencia, que está determinada por la relación fuerza-velocidad. Por lo tanto, la potencia puede mejorarse aumentando la capacidad para desarrollar altos niveles de fuerza a bajas velocidades y/o mejorando la velocidad de movimiento. En este sentido, uno de los métodos de entrenamiento más utilizados por los entrenadores y preparadores físicos en el fútbol es el entrenamiento resistido, caracterizado por permitir al atleta replicar el patrón de movimiento del ejercicio con una sobrecarga adicional, lo que proporciona una sobrecarga mecánica específica de los movimientos deportivos. Sin embargo, son pocos los estudios que han analizados los efectos y adaptaciones que producen las diferentes modalidades de entrenamiento resistido en jugadores de fútbol. Por ello, la presente tesis doctoral pretende revisar el estado de la literatura en relación a los estudios de intervención, que han analizado los efectos del entrenamiento resistido sobre el rendimiento de esprint, diseñar una herramienta para el control y la prescripción del entrenamiento resistido, describir los efectos agudos del incremento de la carga del sobre las variables espacio-temporales y cinéticas; así como, determinar el rango de carga más apropiado para conseguir las adaptaciones deseadas cuando se aplique este método de entrenamiento y comparar los efectos del uso de diferentes modalidades de entrenamiento resistido, y la combinación de ellas sobre el rendimiento en el esprint, la habilidad para cambiar de dirección y la capacidad de salto. Los resultados obtenidos permiten concluir que el entrenamiento resistido es un método eficaz para mejorar el rendimiento de esprint, cambio de dirección y salto. Sin embargo, se debe tener en cuenta que, según el objetivo perseguido, será conveniente el uso de unas modalidades u otras, así como la combinación de las mismas. Además, esta tesis aporta una herramienta, a modo de ecuación, que permite controlar y prescribir el entrenamiento resistido con precisión y establecer el rango de carga adicional que se debe añadir en función del objetivo perseguido.Actividad Física y Deport
Health benefits of zumba: A systematic review
El objetivo de la presente revisión sistemática fue resumir y analizar los beneficios para la salud, tanto a nivel físico como psicológico, de una actividad colectiva tan popular y practicada a día de hoy, como es el Zumba. Para ello, se realizó una búsqueda en la base de datos Medline/Pubmed para encontrar todos los estudios publicados hasta el 15 de noviembre de 2016 bajo la palabra clave “Zumba”. Se encontraron 15 publicaciones que cubrían los criterios de inclusión. Según el estado actual de la literatura científica, practicar Zumba reporta beneficios significativos a nivel antropométrico (disminuye el índice de masa corporal), en la composición corporal (disminuyendo la grasa corporal), en la condición física (aumenta el consumo máximo de oxígeno), a nivel de calidad de vida (autopercepción física y bienestar psicológico). Por todo ello, se pude concluir que practicar Zumba repercute positivamente para la salud, y se recomienda que sea llevada a cabo por un monitor, ya que los beneficios son mayores que cuando se práctica siguiendo las directrices de un DVD.The purpose of this systematic review was to summarize and analyse the health benefits, both physical and psychological, a collective activity so popular and practiced today as is the Zumba. For this purpose, a search was conducted in Medline/Pubmed database to find all the studies published until 15 November 2016, under the key word "Zumba". 15 publications covering the inclusion criteria were found. As it is current state of the literature on this topic, the main benefits of this activity occur significantly to anthropometric level (decreases the body mass index), body composition (decreases the body fat), fitness (increase the maximum oxygen consumption), as well as also the parameters of quality of life (physical self-perception and psychological well-being). Therefore, the conclusion is that the Zumba practice has a positive impact on health, and it is recomended to do it with an instructor because there are more benefits than to practice in front of a DVD.peerReviewe
Risk of hypertension and Use of antihypertensive drugs in the physically active population under-70 years old—spanish health survey
Introduction: Reducing the prevalence of hypertension is a major priority of the World
Health Organization (WHO). Its high prevalence and associated risks generate high economic and
social costs. Physical activity (PA) is associated with a decrease in hypertension and in the use of
antihypertensive drugs. Objective: To explore the association between PA levels (PAL), prevalence
of hypertension and the use of antihypertensive drugs in Spanish population. To calculate risks
of hypertension and use of antihypertensive in the inactive versus physically active population.
Method: This cross-sectional study used data from 17717 individuals, sampled in the 2017 National
Health Survey. Interaction by sex, age groups, body mass index (BMI), hypertension prevalence,
antihypertensive drugs use and PAL, using a pairwise z-test, and dependence relationships between
variables, were studied using a chi square test. Odds ratios of hypertension and antihypertensive drug
use were calculated among the inactive and the physically active populations. Results: The findings
showed a significant inverse association between prevalence of hypertension, antihypertensive use,
and PAL in both sexes and different age and BMI groups, with lower prevalence of hypertension and
antihypertensive use when PAL were higher. The risks of hypertension and antihypertensive use
seems to be reduced when related to higher PAL compared to inactive people. Conclusions: High
PAL is associated with lower prevalence of hypertension and lower antihypertensive use. Thus, being
physically active or very active may reduce the risks of suffering from hypertension and the need to
use antihypertensives compared to inactive people or walkersinfo:eu-repo/semantics/publishedVersio
Effect of acute Ramadan fasting on muscle function and buffering system of male athletes
The aim of this study was to investigate the effect of acute Ramadan fasting (RF) on the muscle function and buffering system. Twelve male athletes with 8 years of professional sports experience (age, 23.2 ± 1.3 years, body mass index: 24.2 ± 2.2 kg/m2) participated in this study. The subjects were tested twice, 3 weeks after the beginning of RF and 2 weeks after the end RF. Muscle function, buffering capacity, and rating of perceived exertion (RPE) were measured during and after RF by using the Biodex isokinetic machine, blood gas analyzer, and RPE 6-20 Borg scale, respectively. Venous blood samples for pH and bicarbonate (HCO3-) were measured during and after RF by using the Biodex isokinetic machine, blood gas analyzer, and RPE 6-20 Borg scale, respectively. Venous blood samples for pH and bicarbonate (HCO3-) were taken immediately after 25 repetitions of isokinetic knee flexion and extension. Measures taken during isokinetic knee extension during RF were significantly lower than those after RF in extension peak torque (t = -4.72, p = 0.002), flexion peak torque (t = -3.80, p = 0.007), extension total work (t = -3.05, p = 0.019), extension average power (t = -4.20, p = 0.004), flexion average power (t = -3.37, p = 0.012), blood HCO3- (t = -2.02, p = 0.041), and RPE (Z = -1.69, p = 0.048). No influence of RF was found on the blood pH (t = 0.752, p = 0.476). RF has adverse effects on muscle function and buffering capacity in athletes. It seems that a low-carbohydrate substrate during RF impairs muscle performance and reduces the buffering capacity of the blood, leading to fatigue in athletes
Intra- and Inter-week Variations of Well-Being Across a Season: A Cohort Study in Elite Youth Male Soccer Players
This study describes the weekly variations of well-being ratings relative to fatigue (wFatigue), stress (wStress), delayed-onset muscle soreness (wDOMS), sleep quality (wSleep), and Hooper questionnaire (wHQ) throughout the season. In addition, the well-being variables for the playing position in different moments of the season were discussed. Twenty-one elite young soccer players U17 took part in this study. From the beginning of the pre-season, well-being status was monitored daily by the HQ method throughout 36 weeks, including four periods: (1) pre-season, (2) early-season, (3) mid-season, and (4) end-season. Players trained at least 3 times per week throughout the season. The main outcome was that, in weeks 33 and 28, the highest [wFatigue: 15.85 +/- 3.38 arbitrary units (AU); wHQ: 48.86 +/- 9.23 AU] and the lowest (wFatigue: 5.38 +/- 1.88 AU; wHQ: 20.43 +/- 5.49 AU) wFatigue and wHQ occurred, respectively, although the lowest level of wDOMS happened in week 28 (4.86 +/- 2.15 AU), while the highest wDOMS was observed in week 5 (14.65 +/- 4.16 AU). The highest wSleep (13.00 +/- 2.12 AU) and wStress (11.65 +/- 2.92 AU) were observed in weeks 8 and 34, respectively, while the lowest wSleep (5.81 +/- 2.29 AU) and wStress (3.76 +/- 0.94 AU) were marked in week 29 coincidentally. In the HQ between every weekday, except recovery day, and the day of the match (MD), considerable highest HQ was only revealed in 2 days after MD in contrast to overall team comparison. In the present study, we observed that the well-being changes between different phases of the season as well as between weeks and days of the week with the MD are significant. These results provide a great point of view for coaches and practitioners about well-being variations over a season in elite youth soccer level. As a result, coaches will be more aware about non-functional overreaching and taking measures to prevent it
Academic Self-Regulation in Three Children with ADHD
The current research aimed to submit a proposal for an intervention based on behavior modification training in academic self-regulation program for elementary school students in order to improve their academic performance. The program was developed through a quantitative methodology in which data were collected through field observations, interval rate records, permanent products and the application of the Self-Regulation Assessment in School Activities Questionnaire (Flores & Cerino, 2000); 22 sixth-grade students participated, divided into two groups (experimental/control) from an urban private elementary school in Merida, Yucatan, Mexico. Within the experimental group, work was focused on three children with disorder Attention Deficit (ADD) and disorder attention deficit with hyperactivity (ADHD) through behavior modification to ensure greater control over their learning process. The results show the effectiveness of the intervention in the students, since it is possible to increase self-regulation in the academic field. From the improvements found in academic performance, it can be concluded that the knowledge of students about their own ability in problem solving and supporting actions that impact on their tasks’ outcomes, are aspects that make a difference have an effect on the academic performance which is reflected in the scorings
Eccentric training as strategy to improve change of direction and sprint performance in team-sports: A systematic review
La presente revisión sistemática pretendió revisar el estado de la literatura
en relación con los estudios que han analizado los efectos de un programa
de entrenamiento excéntrico sobre el rendimiento en el cambio de
dirección (COD) y el esprint en deportes de equipo, y explorar cuáles
podrían ser las características más adecuadas para conseguir las mayores
adaptaciones. Para ello, se realizó una búsqueda en diferentes bases de
datos: PubMed, Scopus, SPORTDiscus y Web of Science, incluyendo los
artículos publicados hasta el 12 de febrero de 2020. Un total de 11 estudios
cumplieron los criterios de elegibilidad. La muestra de todos los estudios
incluidos estaba compuesta por sujetos sanos físicamente activos y
practicantes de deportes de equipo, de género masculino, con edad
superior a 16 años y, nivel de práctica variado. Los resultados muestran que
el entrenamiento excéntrico puede ser una estrategia adecuada para
mejorar el COD y el esprint en deportes de equipo. Concretamente, aplicar
el método excéntrico durante al menos 5 semanas, con una frecuencia de
2-3 días a la semana podría favorecer las mayores mejoras en el COD. Sin
embargo, la heterogeneidad de los protocolos de entrenamiento no
permite determinar qué volumen de entrenamiento sería el más idóneo
para favorecer mejoras en el COD. Así mismo, aplicar entrenamiento
excéntrico durante al menos 5 semanas, con una frecuencia de 1-3 días a la
semana y volumen de 1-4 series de 5-16 repeticiones podría favorecer las
mejoras en el esprintThe present systematic review aimed to review the state of the literature in relation to studies that
have analysed the effects of an eccentric training program on change of direction (COD) and sprint
performance in team-sports, and to explore what might be the most appropriate characteristics to
achieve the greatest adaptations on performance. A search was conducted in different databases:
PubMed, Scopus, SPORTDiscus and Web of Science, including articles published up to 12 February
2020. A total of 11 studies met the eligibility criteria. The sample of all the included studies was
composed of healthy physically active male team-sports subjects, over 16 years old, with different
level of practice. Results show that eccentric training may be an appropriate strategy to improve COD
and sprint performance in team-sports. Specifically, applying the eccentric method for at least 5
weeks, with a training frequency of 2-3 days per week, could lead to the greatest improvements in
COD. However, the heterogeneity of the training protocols does not allow us to determine which
volume of training would be most suitable to promote improvements in COD. Likewise, applying
eccentric training for at least 5 weeks, with a frequency of 1-3 days per week, with a volume of 1-4
series of 5-16 repetitions could favour improvements in sprint performanc
Discovery of distant RR Lyrae stars in the Milky Way using DECam
We report the discovery of distant RR Lyrae stars, including the most distant
known in the Milky Way, using data taken in the band with the Dark Energy
Camera as part of the High cadence Transient Survey (HiTS; 2014 campaign). We
detect a total of 173 RR Lyrae stars over a ~120 deg^2 area, including both
known RR Lyrae and new detections. The heliocentric distances d_H of the full
sample range from 9 to >200 kpc, with 18 of them beyond 90 kpc. We identify
three sub-groups of RR Lyrae as members of known systems: the Sextans dwarf
spheroidal galaxy, for which we report 46 new discoveries, and the ultra-faint
dwarf galaxies Leo IV and Leo V. Following an MCMC methodology, we fit
spherical and ellipsoidal profiles of the form rho(R) ~ R^n to the radial
density distribution of RR Lyrae in the Galactic halo. The best fit corresponds
to the spherical case, for which we obtain a simple power-law index of
n=-4.17^{+0.18}_{-0.20}, consistent with recent studies made with samples
covering shorter distances. The pulsational properties of the outermost RR
Lyrae in the sample (d_H>90 kpc) differ from the ones in the halo population at
closer distances. The distribution of the stars in a Period-Amplitude diagram
suggest they belong to Oosterhoff-intermediate or Oosterhoff II groups, similar
to what is found in the ultra-faint dwarf satellites around the Milky Way. The
new distant stars discovered represent an important addition to the few
existing tracers of the Milky Way potential in the outer halo.Comment: Accepted for publication in The Astrophysical Journa
Short-Term Branched-Chain Amino Acid Supplementation Does Not Enhance Vertical Jump in Professional Volleyball Players. A Double-Blind, Controlled, Randomized Study
To the best of the author's knowledge, no previous studies have described the effect of branched-chain amino acids (BCAA) on vertical performance during a week in professional volleyball players. This study assessed BCAA supplementation for a week, aiming to improve vertical jump performance in male professional volleyball players. Twelve male volleyballers were randomly assigned to a BCAA group (n = 6) or a control group (n = 6). The BCAA group ingested 21 g over a week, 7 g per day on Monday, Wednesday, and Friday, before a volleyball training session, while the control group drank a placebo drink. Participants performed 8 maximal countermovement jumps (CMJ); the 3 CMJs on Monday and Wednesday were evaluated after warm-up, after plyometric training, and at the end of the training session; and the 2 CMJs on Friday were evaluated after warm-up, and at the end of the training session. Compared with baseline, no significant differences in CMJ over the week were observed in BCAA or control group, neither between groups. The results indicated that 21 g of BCAA supplementation over a week did not improve vertical jump performance in professional volleyball players.Hasta donde los autores saben, no se han descrito estudios previos sobre el efecto de los aminoácidos ramificados (BCAA) en el rendimiento
vertical durante una semana en jugadores de voleibol profesionales. Este artículo estudió la suplementación de BCAA durante una semana con el
objeto de mejorar el rendimiento del salto vertical en jugadores de voleibol profesionales masculinos. Doce jugadores de voleibol masculinos se
asignaron aleatoriamente a un grupo con BCAA (n = 6) o a un grupo de control (n = 6). El grupo con BCAA ingirió 21 g en una semana, 7 g por
día los lunes, miércoles y viernes antes de la sesión de entrenamiento de voleibol, mientras que el grupo de control bebió una bebida placebo. Los
participantes realizaron 8 saltos máximos de contramovimiento (CMJ); los 3 CMJ de lunes y miércoles se evaluaron después del calentamiento
y del entrenamiento pliométrico, y al final de la sesión de entrenamiento; los 2 CMJ del viernes se evaluaron después del calentamiento y al final
de la sesión de entrenamiento. En comparación con el valor inicial, no se observaron diferencias significativas en los CMJ a lo largo de la semana,
ni en el grupo BCAA ni en el grupo control, tampoco hubo diferencias entre grupos. Los resultados indicaron que 21 g de BCAA administrados
durante una semana no mejoraron el rendimiento del salto vertical en jugadores de voleibol profesionale
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