Training load and injury incidence over one season in adolescent Arab table tennis players : a pilot study

Background: It has been established that injury incidence data and training load in table tennis is somewhat limited. Objectives: The purpose of this study was to analyze and report training load and injury incidence. This was established over a full season in highly trained youth table tennis athletes. We further aimed to establish what variables related to training load have a statistically significant effect on injury in youth table tennis. Methods: Data was collected from eight male adolescent table tennis players of Arabic origin. Training and game time were monitored continuously throughout each training session and match. Heart rate was measured throughout and then subsequently analyzed to quantify internal training load. Results: Players were subjected to an average of 1901 h 33 min ± 44 h 30 min of training time and 140 h 0 min ± 11 h 29 min of game time over the season. Overall injury incidence was 8.3 (95% CI: 4.6 - 12.0), time-loss injuries 4.4 (95% CI: 1.9 - 6.9) and growth conditions 2.0 (95% CI: 0.6 - 3.3) per 1000 hours. Internal training loads quantified via the Edwards training impulse equation were significantly different between training weeks (P = 0.001), with lowest values around competition periods (P < 0.05). For every extra auxiliary unit of relative training load per minute during training, a significant increase (P = 0.014) in injury occurrence was present. Conclusions: Most of the injuries occurred during the first quarter of the year (65%), when training loads were highest. In conclusion, the results of this preliminary study showed that training loads increase during a season until competition period, with relative training load per minute being linked to the likelihood of injuries. The rate of overuse injuries and growth-related conditions were higher than previously reported in adolescents in other racket sports

Somatotype and Body Composition of Indian Male and Female Swimmers, and their Relationship to Countermovement Jump Performance

Introduction: The aim of this study was:1) to ascertain the anthropometric characteristics of Indian swimmers and 2) to investigate the potential association between these characteristics and countermovement jump metrics. Method: Forty-two national level Indian swimmers (18 females and 24 males) who regularly compete in national and/or international competitions, took part in the study. Anthropometric measurements were performed for body mass, stature, 8 skinfold sites, 3 girths, and 2 breadths. Somatotypes, body fat %, fat mass and lean body mass for all athletes were also calculated. A CMJ test was performed to measure vertical jump height, peak power output, and relative peak power output. Results: The Pearson correlation analysis of body composition variables and CMJ measures revealed a very large negative association between body fat percent and vertical jump height (R = - 0.726; p = 0.000) and between body fat percent and relative peak power (R = -0.757; p = 0.000); a large negative association between body fat percent and peak power (R = - 0.577; p = 0.000) and between fat mass and relative peak power (R = -0.560, p = 0.000); a moderately negative association between fat mass and vertical jump height (R = -0.490, p = 0.001); a very large positive association between lean body mass and peak power (R = 0.862, p = 0.000); and a large positive association between lean body mass and vertical jump height (R = 0.599, p = 0.000) and a large positive association between lean body mass and relative peak power (R = 0.530, p = 0.000); and a moderately positive association between BMI and peak power (R = 0.413, p = 0.007). Conclusion: There are significant differences in anthropometric characteristics when analyzing the anthropometric characteristics of Indian swimmers which could be attributed to the specific demands of each event. Anthropometric characteristics and body composition differences influence swim performance and vary according to gender, age and maturation status. A robust and significant positive correlation exists between lean body mass and vertical jump height suggesting that an enhancement of an individual's lean mass seems to have a positive impact on lower body power production in swimmers. Individualised training plans that focus on lower limb strength will have a potential positive effect on swim performance.Introducción: El objetivo de este estudio fue: 1) determinar las características antropométricas de los nadadores indios y 2) investigar la posible asociación entre estas características y las métricas de salto con contramovimiento. Método: Participaron en el estudio cuarenta y dos nadadores indios de nivel nacional (18 mujeres y 24 hombres) que compiten regularmente en competiciones nacionales y/o internacionales. Se realizaron mediciones antropométricas de masa corporal, estatura, 8 sitios de pliegues cutáneos, 3 circunferencias y 2 anchuras. También se calcularon los somatotipos, el porcentaje de grasa corporal, la masa grasa y la masa corporal magra de todos los sujetos. Se realizó una prueba CMJ para medir la altura del salto vertical, la producción de potencia máxima y la producción de potencia máxima relativa. Resultados: El análisis de correlación de Pearson de las variables de composición corporal y las medidas CMJ reveló una asociación negativa muy grande entre el porcentaje de grasa corporal y la altura del salto vertical (R = - 0,726; p = 0,000) y entre el porcentaje de grasa corporal y la potencia máxima relativa (R = - 0,757;p=0,000); una gran asociación negativa entre el porcentaje de grasa corporal y la potencia máxima (R = -0,577; p = 0,000) y entre la masa grasa y la potencia máxima relativa (R = -0,560, p = 0,000); una asociación moderadamente negativa entre la masa grasa y la altura del salto vertical (R = -0,490, p = 0,001); una asociación positiva muy grande entre la masa corporal magra y la potencia máxima (R = 0,862, p = 0,000); y una gran asociación positiva entre la masa corporal magra y la altura del salto vertical (R = 0,599, p = 0,000) y una gran asociación positiva entre la masa corporal magra y la potencia máxima relativa (R = 0,530, p = 0,000); y una asociación moderadamente positiva entre el IMC y la potencia máxima (R = 0,413, p = 0,007). Conclusión: Existen diferencias significativas en las características antropométricas al analizar las características antropométricas de los nadadores indios que podrían atribuirse a las demandas específicas de cada evento. Las características antropométricas y las diferencias en la composición corporal influyen en el rendimiento en natación y varían según el sexo, la edad y el estado de maduración. Existe una correlación positiva sólida y significativa entre la masa corporal magra y la altura del salto vertical, lo que sugiere que una mejora de la masa magra de un individuo parece tener un impacto positivo en la producción de potencia de la parte inferior del cuerpo en los nadadores. Los planes de entrenamiento individualizados que se centran en la fuerza de las extremidades inferiores tendrán un efecto potencial positivo en el rendimiento en natación

Anthropometric characteristic, somatotype, and body composition of Indian Female Combat Sport Athletes: A comparison between Boxers, Judokas, and Wrestlers

Introduction: The aim of this study was:1) to ascertain the anthropometric characteristics of Indian female combat athletes and 2) to determine and compare the sport-specific (boxing, judo, and wrestling) somatotype of Indian female combat athletes. Method: Ninety-nine national level female combat sports athletes (40 Boxers, 25 Judokas, and 34 Wrestlers who regularly compete in national and/or international competitions, took part in the study. Anthropometric measurements were performed for body mass, stature, 7 skinfold sites, 3 girths, and 2 breadths. Somatotypes for all subjects were also calculated. All measurements were statistically analyzed using pairwise comparison analysis and differences between groups were also compared. Results: Significant differences between boxing and judo for the mean value of BMI. Pairwise comparison analysis revealed significant differences in the mesomorphy component between boxing and judo (p = 0.001; 95% CI: -1.83 – -0.40) and between boxing and wrestling (p = 0.001; 95% CI: -1.69 – -0.39); as well as in the ectomorphy component between boxing and judo (p = 0.009; 95% CI: 0.16 – 1.35) and between boxing and wrestling (p = 0.007; 95% CI: 0.17 – 1.25). Conclusion: There are significant differences in anthropometric characteristics when analyzing the somatotype of Indian female combat athletes which could be attributed to the specific demands of each sport. Sport-specific training programmes that consider the anthropometric characteristics and somatotype of female athletes participating in Boxing, Judo and Wrestling should be considered by practitioners and coaches.Introducción: El objetivo de este estudio fue: 1) analizar las características antropométricas de las atletas de combate indias y 2) determinar y comparar el somatotipo específico del deporte (boxeo, judo y lucha libre) de las atletas de combate indias. Método: Noventa y nueve atletas de deportes de combate de nivel nacional (40 boxeadoras, 25 judocas y 34 luchadoras que competían regularmente en competencias nacionales y/o internacionales participaron en el estudio. Se realizaron mediciones antropométricas de masa corporal, estatura, 7 sitios de pliegues cutáneos, 3 perímetros y 2 diámetros. También se calculó el somatotipo para todos los sujetos. Todas las mediciones se analizaron estadísticamente mediante un análisis de comparación por pares y se estudiaron las diferencias entre los grupos. Resultados: Se hallaron diferencias significativas entre el boxeo y el judo para el valor medio del IMC. El análisis de comparación por pares reveló diferencias significativas en el componente mesomorfo entre el boxeo y el judo (p = 0,001; 95% IC: -1,83 – -0,40) y entre el boxeo y la lucha libre (p = 0,001; 95 % IC: -1.69 – -0.39); así como también en el componente ectomorfo entre el boxeo y el judo (p = 0.009; 95% CI: 0.16 – 1.35) y entre el boxeo y la lucha libre (p = 0.007; 95% CI: 0.17 – 1.25). Conclusión: Existen diferencias significativas en las características antropométricas al analizar el somatotipo de las atletas de combate indias, estas podrían atribuirse a las demandas específicas de cada deporte. Los practicantes y entrenadores deben considerar los programas de entrenamiento específicos del deporte teniendo en cuenta las características antropométricas y el somatotipo de las atletas que participan en el boxeo, el judo y la lucha libre

The prevalence of musculoskeletal injuries in junior elite squash players

Background: The dynamics and competitiveness of squash place a high demand on the musculoskeletal system of players, thus increasing the injury risk of youth squash players. Objectives: The purpose of this study was to analyze and report the musculoskeletal injury epidemiology of junior elite squash players. Methods: Twenty-one male adolescent squash players were included in this retrospective analysis of routinely collected data over a period of 6-years. Origin, location, diagnosis and incidence of all injuries are reported. Results: A total of 212 injuries were recorded: 58% of these injuries (n = 124) were squash (on-court) related, 16% (n = 33) were because of other training activities and 26% of these injuries were (n = 55) non-squash related. Most of squash related training injuries were in the lower limbs (67%, n = 105). The most frequently reported diagnosis was “osteochondrosis” (22%, n = 34), followed by “contusion” (13%, n = 20). Time-loss injuries accounted for 103 injuries and the overall injury incidence was 4.78 per 1000 hours of training. Conclusions: It was established that pre-mature squash players are at greater risk of growth related injuries during their peak growth period. A significant number of injuries at junior level are found to occur outside of training time and result in periods of time loss. As a result, skill acquisition is negatively affected which in turn negatively affects development opportunities in junior athletes

Anthropometric characteristics and 20-m sprint times among Malaysian University athletes

Introduction: The aim of this study was to evaluate the anthropometric characteristics of the Malaysian University level athletes and to explore potential relationships between the anthropometric measures and 20-m linear sprint performance. Method: Forty male Malaysian University level athletes associated with Malaysian Universities and regularly competing in state level competitions took part in the study. Anthropometric measurements were performed for body mass, stature, 8 skinfold sites, 3 girths, and 2 breadths. Somatotype, body fat % and sum of skinfolds were calculated. A 20-m linear sprint test was performed to assess acceleration and running speed. Results: The pairwise comparison analysis revealed that throwers had significant differences in endomorphy with athletes competing in sprinting, karate, and middle distance (p ˂ 0.05), in mesomorphy with athletes competing in long distance, middle distance, sprinters, footballers and karate (p ˂ 0.05), and in ectomorphy with athletes competing in middle distance and karate. The Pearson correlation coefficient between Body Fat Percent and Sprint Time was found to be 0.374 (p = 0.025, two-tailed), indicating a statistically significant positive correlation between the two variables. Conclusion: Physique is highly correlated with the physical characteristics and the development of the athletic functions required in each sport and is a determinant of success. Body fat percentage influences the ability of an individual to accelerate and run maximally.Introducción: El objetivo de este estudio fue evaluar las características antropométricas de atletas de nivel universitario de Malasia y explorar las relaciones potenciales entre las medidas antropométricas y el rendimiento en el sprint lineal de 20 m. Método: Participaron en el estudio cuarenta atletas masculinos de nivel universitario malasios asociados con universidades de Malasia y que compiten regularmente en competencias a nivel estatal. Se realizaron mediciones antropométricas de masa corporal, estatura, 8 sitios de pliegues cutáneos, 3 circunferencias y 2 anchuras. Se calculó el somatotipo, el % de grasa corporal y la suma de pliegues cutáneos. Se realizó una prueba de sprint lineal de 20 m para evaluar la aceleración y la velocidad de carrera. Resultados: El análisis de comparación por pares reveló que los lanzadores tuvieron diferencias significativas en endomorfia con los atletas que compiten en sprint, kárate y media distancia (p˂ 0,05), en mesomorfia con los atletas que compiten en larga distancia, media distancia, velocistas, futbolistas y kárate ( p ˂ 0,05), y en ectomorfia con atletas que compiten en media distancia y kárate. Se encontró que el coeficiente de correlación de Pearson entre el porcentaje de grasa corporal y el tiempo de sprint era 0,374 (p = 0,025, de dos colas), lo que indica una correlación positiva estadísticamente significativa entre las dos variables. Conclusión: El físico está altamente correlacionado con las características físicas adecuadas para los eventos deportivos específicos y el desarrollo de las funciones atléticas requeridas en cada deporte y determina el éxito dentro de cada deporte. El porcentaje de grasa corporal influye en la capacidad de un individuo para acelerar y correr al máximo, y las características antropométricas afectan en última instancia el rendimiento

Sports injuries aligned to predicted mature height in highly trained Middle-Eastern youth athletes: a cohort study

Objectives To investigate the association of maturity status with injury incidence in Middle-Eastern youth athletes. Design Prospective cohort study. Setting Four consecutive seasons (2010-2014), Aspire Academy, Qatar. Participants Male athletes (age range: 11-18 years) representing four disciplines enrolled and grouped into two categories: Individual sports and racquet sports. Outcome measures Injury data collected over four seasons. Athletes' anthropometric characteristics assessed to calculate age at peak height velocity. Predicted mature heights (PMHs) collected and categorised into four quartiles. Athletes had wrist and hand radiographs for assessment of skeletal age (SA). Early and late maturers with an SA of >1 year older or younger than their chronological age (CA). Results For the sample (n=67) across all groups, 43 (64%) athletes had one or more injuries: Total of 212 injuries, 4.9 injuries per athlete across study. Survival analysis of maturity status using SA found early maturing athletes had two-fold greater injury risk compared with late maturers (HR 2.04, 95% CI 1.15 to 3.61, p=0.015). PMH associated with injury risk (HR 1.05, 95% CI 1.01 to 1.08, p=0.006). Athletes in fourth quartile (≥184 cm) had up to two-fold injury risk (HR 2.41, 95% CI 1.42 to 4.08, p=0.001). Racquet and individual sports involved similar injury risk (HR 1.14, 95% CI 0.86 to 1.52, p=0.37). Conclusion SA early maturity and PMH gradient were significant predictors of injury in youths

Circadian variation in muscle force output in males using isokinetic, isometric dynamometry: can we observe this in multi-joint movements using the muscleLab force-velocity encoder and are they similar in peak and magnitude?

We have investigated the magnitude of circadian variation in Isokinetic and Isometric strength of the knee extensors and flexors, as well as back squat and bench press performance using the MuscleLab force velocity transducer. Ten resistance-trained males (mean±SD: age 21.5 ± 1.1 years; body mass 78.3 ± 5.2 kg; height 1.71 ± 0.07 m) underwent a) three to four familiarization sessions on each dynamometer and b) four sessions at different times of day (03:00, 09:00, 15:00 and 21:00 h). Each session was administered in a counterbalanced order and included a period when Perceived onset of mood states (POMS), then rectal and muscle temperature (Trec, Tm) was measured at rest, after which a 5-min standardized 150 W warm-up was performed on a cycle ergometer. Once completed, Isokinetic (60 and 240°·s−1 for extension and flexion) and Isometric dynamometry with peak torque (PT), time-to-peak-torque (tPT) and peak force (PF) and % activation was measured. Lastly, Trec and Tm were measured before the bench press (at 30, 50 and 70 kg) and back squat (at 40, 60 and 80 kg) exercises. A linear encoder was attached to an Olympic bar used for the exercises and average force (AF), peak velocity (PV) and time-to-peak-velocity (tPV) were measured (MuscleLab software; MuscleLab Technology, Langesund, Norway) during the concentric phase of the movements. Five-min recovery was allowed between each set with three repetitions being completed. General linear models with repeated measures and cosinor analysis were used to analyse the data. Values for Trec and Tm at rest were higher in the evening compared to morning values (Acrophase Φ: 16:35 and 17:03 h, Amplitude A: 0.30 and 0.23°C, Mesor M: 36.64 and 37.43°C, p < 0.05). Vigor, happy and fatigue mood states responses showed Φ 16:11 and 16:03 h and 02:05 h respectively. Circadian rhythms were apparent for all variables irrespective of equipment used where AF, PF and PT values peaked between 16:18 and 18:34 h; PV, tPV and tPT peaked between 05:54 and 08:03 h (p < 0.05). In summary, circadian rhythms in force output (force, torque, power, and velocity) were shown for isokinetic, isometric dynamometers and complex multi-joint movements (using a linear encoder); where tPV and tPT occur in the morning compared to the evening. Circadian rhythms in strength can be detected using a portable, low-cost instrument that shows similar cosinor characteristics as established dynamometers. Hence, muscle-strength can be measured in a manner that is more directly transferable to the world of athletic and sports performance

Effects of an active warm-up on variation in bench press and back squat (upper and lower body measures).

The present study investigated the magnitude of diurnal variation in back squat and bench press using the MuscleLab linear encoder over three different loads and assessed the benefit of an active warm-up to establish whether diurnal variation could be negated. Ten resistance-trained males underwent (mean ± SD: age 21.0 ± 1.3 years, height 1.77 ± 0.06 m, and body mass 82.8 ± 14.9 kg) three sessions. These included control morning (M, 07:30 h) and evening (E, 17:30 h) sessions (5-min standardized warm-up at 150 W, on a cycle ergometer), and one further session consisting of an extended active warm-up morning trial (ME, 07:30 h) until rectal temperature (Trec) reached previously recorded resting evening levels (at 150 W, on a cycle ergometer). All sessions included handgrip, followed by a defined program of bench press (at 20, 40, and 60 kg) and back squat (at 30, 50, and 70 kg) exercises. A linear encoder was attached to an Olympic bar used for the exercises and average force (AF), peak velocity (PV), and time to peak velocity (tPV) were measured (MuscleLab software; MuscleLab Technology, Langesund, Norway) during the concentric phase of the movements. Values for Trec were higher in the E session compared to values in the M session (Δ0.53 °C, P  0.05) to increase from M to E levels. Therefore, MuscleLab linear encoder could detect meaningful differences between the morning and evening for all variables. However, the diurnal variation in bench press and back squat (measures of lower and upper body force and power output) is not explained by time-of-day oscillations in Trec

Controlling rectal and muscle temperatures: Can we offset diurnal variation in repeated sprint performance?

The present study investigated whether increasing morning rectal temperatures (Trec) to resting.evening levels, or decreasing evening Trec or muscle (Tm) temperatures to morning values, would influence repeated sprint (RS) performance in a causal manner. Twelve trained males underwent five sessions [age (mean ± SD) 21.8 ± 2.6 yr, peak oxygen uptake ( peak) 60.6 ± 4.6 mL kg min−1, stature 1.78 ± 0.07 m and body mass 76.0 ± 6.3 kg]. These included a control morning (M, 07:30 h) and evening (E, 17:30 h) session (5-min warm-up), and three further sessions consisting of a warm-up morning trial (ME, on a motorised treadmill) until Trec reached evening levels; and two cool-down evening trials (in 16–17°C water) until Trec (EMrec) or Tm (EMmuscle) values reached morning temperatures, respectively. All sessions included a 3 × 3-s task-specific warm-up followed by 10 × 3-s RS with 30-s recoveries performed on a non-motorised treadmill. Trec and Tm measurements were taken at the start of the protocol and following the warm-up or cool-down period. Values for Trec and Tm were higher in the evening compared to morning values (0.45°C and 0.57°C, P < 0.05). RS performance was lower in the M for distance covered (DC), average power (AP) and average velocity (AV) (9–10%, P < 0.05). Pre-cooling Trec and Tm in the evening reduced RS performance to levels observed in the morning (P < 0.05). However, an active warm-up resulted in no changes in morning RS performance. Diurnal variation in Trec and Tm is not wholly accountable for time-of-day oscillations in RS performance on a non-motorised treadmill; the exact mechanism(s) for a causal link between central temperature and human performance are still unclear and require more research