The influence of maturity on recovery and perceived exertion, and its relationship with illnesses and non-contact injuries in young soccer players

A high training load could increase the risk of injury in soccer players. However, there is still a lack of knowledge regarding the effect on young athletes, in whom a different maturity status could lead to different physiological responses to training. Therefore, the aim of this study was to investigate the association of internal load markers and recovery status with risk of illnesses and non-contact injuries in young soccer players characterised by different maturity status. Twenty-three U14 soccer players were monitored during a full season and categorised according to years from peak height velocity (PHV). Based on the estimated values, athletes were divided into three different groups: Pre-PHV, Circa-PHV and Post-PHV players. The following internal load markers were monitored: rating of perceived exertion (RPE), session rating of perceived exertion (S-RPE), weekly load (WL), cumulative loads for 2, 3, and 4 weeks (WL2, WL3, WL4), acute to chronic workload ratio for 2, 3 and 4 weeks (A:C2, A:C3, A:C4) and week-to-week percentage variation (%WL). Recovery status was quantified using the total quality recovery (TQR) scale. Z-score transformation was adopted for TQR and RPE values and the difference between the parameters was calculated (Z-TQR-RPE). The Kruskal-Wallis test was adopted to evaluate differences in TQR and RPE with respect to maturity offset. A multinomial regression analysis was performed to evaluate the association between internal load markers and risk of illness and non-contact injuries. The variables that showed a significant association were included in the receiver operating characteristic (ROC) curve analysis. The results revealed that RPE was significantly higher (p < 0.01) and TQR significantly lower (p < 0.05) in Post-PHV compared to Pre- and Circa-PHV. Moreover, RPE, A:C4, TQR and Z-TQR-RPE showed a significant (p < 0.01) association with non-contact injuries. The internal load markers included in ROC curve analysis showed poor predictive ability (AUC ≤ 0.6). A rapid increase in training load together with a decrease in recovery status may produce higher susceptibility to illnesses and non-contact injuries. The contrasting physiological responses found in relation to maturity status could explain the different injury predisposition in young soccer players

Efecto del género y del resultado final del partido en competiciones profesionales de pádel

The present study aimed at analyzing the technical and tactical aspects of professional padel matches in relation to gender and match outcome. For this purpose, a notational analysis was performed on 22 official matches of the World Padel Tour 2016 by means of 18 technical and tactical indicators. A non-parametric approach was applied to evaluate differences (P ≤ 0.05) between gender and match outcome subgroups. For gender, differences emerged for the occurrence (P<0.001) and duration (P<0.001) of rallies, backhand strokes (P=0.02) and backhand volley (P=0.027), strokes close to net (P=0.001) and from midfield zone (P=0.012), smashes determining ball out (P<0.001), and first service faults (P<0.001). For match outcome, a difference was found only for the occurrence of winning rallies (in general: P<0.001; in female performance: P=0.009; in male performance: P=0.001). Although findings highlight that padel performance can be discriminated only for gender, whereas winning and losing performances resulted similar, probably for the influence of different playing styles, this study could represent a valuable reference for further analyses and more effective padel training plans.El presente estudio tuvo como objetivo analizar aspectos técnicos y tácticos en pádel profesional en relación con el género y el resultado final del partido. Para ello, se realizó un análisis notacional de 22 partidos oficiales del circuito profesional World Padel Tour 2016 registrando 18 indicadores técnicos y tácticos. Se llevó a cabo un análisis no paramétrico de los datos para comparar las diferencias (P ≤ 0.05) entre los subgrupos de género y resultado final. Para el género, se encontraron diferencias en el número (P<0.001) y duración (P<0.001) de los rallies, golpes de revés (P=0.02) y voleas de revés (P=0.027), golpes cerca de la red (P<0.001) y golpes desde la zona intermedia del campo (P=0.012), remates ganadores por bola fuera del campo (P<0.001) y faltas de primer saque (P<0.001). Para el resultado del partido, se encontraron diferencias únicamente en el número de rallies ganadores (en general: P<0.001; en mujeres: P=0.009; en hombres: P=0.001). Los resultados obtenidos ponen de manifiesto importantes diferencias en el rendimiento de pádel en cuanto al género, observando resultados similares entre ganadores y perdedores probablemente como consecuencia de diferentes estilos de juego. Este estudio por tanto puede servir como referencia válida para el desarrollo tanto de futuros análisis como de planes de entrenamiento más efectivos en pádel

Perfiles de rendimiento en hit ball de elite: aspectos técnicos, tácticos y frecuencia cardíaca, y los efectos de la competición en la capacidad de salto y rendimiento de fuerza

This study aimed to define a performance profile of elite hit ball matches. Eighty-six male Italian Serie A hit ball players (29.3±5.0 yrs) participated in the study. A technical and tactical analysis (18 indicators) was performed on eleven matches; heart rate (HR) was monitored during matches on 25 players; countermovement jump (CMJ) and maximal grip strength (GS) were measured on all participants before and after match. Differences (P<0.05) between winning (W) and losing (L) teams for technical and tactical analysis (Chi-square), and between match phases for HR, CMJ, and GS (ANOVA for repeated measurements) were tested. Hit ball teams meanly performed 297±10 rallies per match (W: 41±6 goals; L: 23±3 goals, P=0.042). No differences between quarters emerged for HR (171-190 bpm for 57±21 % of match duration). Opposite trends emerged for CMJ (after: 36.2±6.3 cm; before: 33.1±4.8 cm; P=0.001) and GS (after: 433±102 N; before: 463±98 N; P=0.018) performances. Findings show that hit ball is performed at high HR intensity, and that CMJ improves and GS declines after matches. This could be determined by a neuromuscular activation of lower limbs and repeated harm concussions due to shots.El estudio tenía como objetivo definir los perfiles de rendimiento en partidos de hit ball de elite. Un total de 81 jugadores italianos de la Serie A (29.3±5.0 años) tomaron parte en el estudio. El análisis técnico y táctico (18 indicadores) se realizó durante once partidos; la variable frecuencia cardíaca (FC) fue monitorizada durante los partidos en 25 jugadores; el test de salto en contramovimiento (SCM) y el test de fuerza máxima de prensión (FMP) se midieron antes y después de cada partido. Las diferencias (P<0.05) entre equipos ganadores (G) y perdedores (P) en los aspectos técnicos y tácticos se realizó mediante el test de Chi-cuadrado, y para las diferencias entre las fases del partido en las variables FC, SCM y FMP se empleó el ANOVA de medidas repetidas. Los resultados mostraron una media de 297±10 rallies por partido (G: 41±6 goles; P: 23±3 goles, P=0.042). No se encontraron diferencias entre los cuartos de juego para la variable FC (171-190 lpm en 57±21 % de la duración del partido). Se encontraron tendencias opuestas para el test SCM (después: 36.2±6.3 cm; antes: 33.1±4.8 cm; P=0.001) y para el test FMP (después: 433±102 N; antes: 463±98 N; P=0.018). Los resultados muestran que el deporte del hit ball se desarrolla con un rendimiento de alta FC, y con mejoras del SCM y descensos del FMP después del partido. Estos resultados pueden estar determinados por la activación neuromuscular de los miembros inferiores y el daño repetido de los golpeos debido a los lanzamientos en los brazos

Notational Analysis of Wheelchair Paralympic Table Tennis Matches

Paralympic table tennis is the third largest paralympic sport for the number of players. Performance analysis was conducted for the rally duration and interval and impact of serve, whilst none investigated the shots distribution among classes of physical impairment. Therefore, the purpose of this study was to conduct a notational analysis of international competitions in relation to the wheelchair classes. Five matches for each wheelchair class (C1-to-C5) were evaluated from 20 elite male right-handed players. Both players for each match were analyzed for the following performance indicators: strokes type, the area of ball bouncing, and the shots outcome. Backhand shots were the most used technique for all classes. The most used strokes for C1 players were backhand and forehand drive and backhand lob, while for C5 players they were backhand and forehand push and backhand topspin. Similar shots distribution was registered for C2-to-C5 players. The central and far-from-the-net zone was mainly reached by the serve for all classes. Errors shots were similar in all classes, whilst winning shots were more frequent in C1. The current notational analysis provided a meaningful performance modelling of indicators for coaches and athletes that can be used to design training programs for each class

Evolution led humans to bipedalism, but we live in a sedentary society: Will “Sunday running” protect us from NCDs at no cost?

Evolution led humans to bipedal stance and movement. However, we live in a sedentary society that strongly challenges our willingness to be physically active. We (mis)understand that being at least a Sunday runner could protect us from sedentary-related diseases, but what if this compromises the healthier life expectancy anyway? Citing Paul Gauguin, we know where we come from and what we are, the question arises about where we are going. And also, how

Monitoring of the preseason soccer period in non-professional players

This study aimed to monitor the training load and to evaluate the fluctuations of straight and change of direction sprinting during a 5-week of the preseason period in 17 non-professional soccer players. Straight 10-m sprint and 15-m zigzag sprint tests were applied six times: at the beginning and on each Friday. Monitoring of the internal training load has been achieved by the Edwards’ TL and the session-RPE, while the external training load was measured by the GPS system. A general prevalence of low-intensity activities within training units and friendly matches were observed, with an increase in high-intensity activities during the last two weeks of the preseason. The performance of both sprint tests decreased during the first three weeks, becoming better at the end of the period, relative to a higher training load scheduled at the beginning of the preseason. Fluctuations in training load emerged along the five weeks with a continuous decrement from the first to the third week, while during the fourth and fifth week a moderate increase was achieved. Moreover, a very large correlation (r=0.71; p<.001) was evident between the Edwards’ TL and the session-RPE, highlighting the usefulness of an easy and valid method to monitor the internal training load. In conclusion, combining the monitoring of training load and the administration of field tests lead to a better distribution of workload, done by the coaching staff, thus avoiding excessive athletes’ overstressing

Anthropometric evaluation in older individuals in relation to their physical activity level

Individuals older than 55 years tend to adopt sedentary lifestyles (European Commission, 2014) and unhealthy eating attitudes (Ahmed and Haboubi, 2010), which lead to an increase of body fat and risks of non-communicable diseases (Rosembloom and Bahnes, 2006; Sallinen et al., 2008). To investigate the association between the level of involvement in physical activity (PA) on anthropometric features with advancing age, height, body mass, waist (WC) and hip (HC) circumference, and triceps skinfold were measured in 20 athletes (training: &gt;5 hr.week-1), 37 physically active (structured PA: 2 hr.week-1), and 42 sedentary (&lt;1 hr.week-1), older individuals (55-84 yrs). Moreover body mass index (BMI), waist-hip (WHi) and waist-height (WHe) ratio, and fat arm index were calculated. A 2 (gender) x 3 (activity level) verified differences (p&lt;0.05) between groups. No difference for gender emerged for BMI, HC, and WHi. Athletes showed lower (p&lt;0.05) BMI, WC, HC, WHi, triceps skinfold, and arm fat index, and higher height values than physically active and sedentary counterparts. For body mass, a difference (p&lt;0.05) emerged only between athletes with respect to sedentary counterpart. No differences emerged between physically active and sedentary groups. Findings indicate that in older ages only a high physical activity level allows controlling the anthropometric features, thus posing senior athletes at a lower risk of related non-communicable diseases

Post-activation Performance Enhancement after a Bout of Accentuated Eccentric Loading in Collegiate Male Volleyball Players

The purpose of this study was to investigate the benefit of post-activation performance enhancement (PAPE) after accentuated eccentric loading (AEL) compared to traditional resistance loading (TR). Sixteen male volleyball athletes were divided in AEL and TR group. AEL group performed 3 sets of 4 repetitions (eccentric: 105% of concentric 1RM, concentric: 80% of concentric 1RM) of half squat, and TR group performed 3 sets of 5 repetitions (eccentric & concentric: 85% of 1RM). Countermovement jump (CMJ), spike jump (SPJ), isometric mid-thigh pull (IMTP), and muscle soreness test were administered before (Pre) exercise, and 10 min (10-min), 24 h (24-h), and 48 h (48-h) after exercise. A two-way repeated measures analysis of variance was used to analyze the data. Peak force and rate of development (RFD) of IMTP in AEL group were significantly greater (p 0.05) groups x time. AEL seemed capable to maintain force production in IMTP, but not in CMJ and SPJ. It is recommended the use of accentuated eccentric loading protocols to overcome the fatigue

Vascular function in the aging human brain during muscle exertion

: To determine how brain oxygenation is stably maintained during advancing age, cerebral oxygenation and hemoglobin were measured real-time at 10 Hz using near-infrared spectroscopy (NIRS) at rest (30 seconds) and during a 10-repeated handgrip strength test (30 seconds) for 834 adults (M/F = 45/55%) aged 20-88 y. The amplitude of cerebral hemodynamic fluctuation was reflected by converting 300 values of % oxygen saturation and hemoglobin of each 30-second phase to standard deviation as indicatives of brain oxygenation variability (BOV) and brain hemodynamic variability (BHV) for each participant. Both BOV (+21-72%) and BHV (+94-158%) increased during the maximal voluntary muscle exertions for all age levels (α &lt; 0.05), suggesting an increased vascular recruitment to maintain oxygen homeostasis in the brain. Intriguingly, BHV was &gt;100 folds for both resting and challenged conditions (α &lt; 0.001) in &gt;80% of adults aged above 50 y despite similar BOV compared with young age counterparts, indicating a huge cost of amplifying hemodynamic oscillation to maintain a stable oxygenation in the aging brain. Since vascular endothelial cells are short-lived, our results implicate a hemodynamic compensation to emergence of daily deficits in replacing senescent endothelial cells after age 50 y