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Explosive strength, velocity and specific motor skills in soccer junior players: A correlational study  [PDF]
M.C. Marques,B. Travassos,R. Almeida
Motricidade , 2010,
Abstract: The main aims of the present study were: a) to evaluate speed and technical skills, and b) to examine the relationship between those measures. Thirty-seven junior soccer players under 19 years of age from three amateur soccer teams were evaluated using vertical and horizontal jump tests, 30m sprint speed test, change of direction test, dribble test and the kicking speed test. The significant correlations found help to understand this population's performance.
SPORT EXERCISE CAPACITY OF SOCCER PLAYERS AT DIFFERENT LEVELS OF PERFORMANCE  [PDF]
Marcin Andrzejewski,Jan Chmura,Tomasz Dybek,Beata Pluta
Biology of Sport , 2012,
Abstract: The aim of the study is to compare the level of exercise capacities to the loads occurring at the lactate threshold among soccer players representing different levels of sport mastery. The research included 51 soccer players representing different levels of sport mastery. The research was conducted at the beginning of the preparatory period for the spring season. A field exercise test of increasing intensity was performed to check the players’ exercise capacities on the soccer pitch. The test enabled us to determine the 4 millimolar lactate threshold (TLA 4 mmol · l-1) on the basis of lactate concentration in blood (LA), and to define the threshold running speed and the threshold heart rate (HR). The lactate level in blood was measured using a Lactate Scout photometer with the enzyme-amperometric method from capillary blood for 20 seconds after each load. The threshold running speed at the level of the 4 millimolar lactate threshold was marked using the two-point form of the equation of a straight line. The conducted tests showed significant differentiation of the threshold running speed among individual teams. The soccer players of a leading first league club were expected to achieve the best result. The conducted tests did not confirm this assumption. Juniors reached the highest threshold running speed of 3.61 m · s-1. Lower values of the analysed indicator were acquired by players of the first league team (3.50 m · s-1) and the lowest by players of the second league team (3.28 m · s-1). Statistically significant differences were noted between the junior group and second league team (p≤ 0.01) and between the first and the second league soccer players (p<0.05).
Vitamin D and Exercise Performance in Professional Soccer Players  [PDF]
Nikolaos E. Koundourakis, Nikolaos E. Androulakis, Niki Malliaraki, Andrew N. Margioris
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0101659
Abstract: Aim The current study had two aims. The primary purpose was to examine the association between serum vitamin D levels and the ergometric evaluation of muscle strength, aerobic capacity, and speed in professional soccer players. The secondary aim was to evaluate the effects of the soccer off-season period on serum vitamin D levels. Methods Sixty-seven Caucasian male soccer players (age 25.6±6.2 and height 1.81±0.08 m), members of two Greek Superleague Soccer teams and one Football-league championship team participated in this study. Exercise performance testing for the determination of squat jump (SJ), countermovement jump (CMJ), 10 (10 m) and 20 meters (20 m) sprint performance, maximal oxygen consumption (VO2max), anthropometry, and blood sampling were performed before (pre) and after (post) the six-week off-season period. Results Analysis of our results showed the following: (a) a significant correlations between serum vitamin D levels and performance parameters in both pre (SJ; P<0.001, CMJ; P<0.001, VO2max; P<0.001, 10 m; P<0.001, and 20 m; P<0.001) and post (SJ; P<0.001, CMJ; P<0.001, VO2max; P = 0.006, 10 m; P<0.001, and 20 m; P<0.001) experimental sessions. (b) Vitamin D concentration increased significantly (P<0.001) following the six-week off-season period compared to baseline, while at the same time all measured performance parameters decreased (SJ; P<0.001, CMJ; P<0.001, 10 m; P<0.001, 20 m; P<0.001, VO2max; P<0.001). Discussion Our findings suggest that vitamin D levels are associated with the ergometric evaluation of muscle strength, as expressed by SJ and CMJ, sprinting capacity, and VO2max in professional soccer players, irrespective the levels of performance. Furthermore, our data reaffirm the importance of UVB on serum vitamin D levels. Moreover, reductions in exercise training stress may also have beneficial effects on vitamin D levels, suggesting a possible association of its levels and the training-induced stress. Our results indicate a possibly bidirectional interaction between soccer performance indices and vitamin D levels.
A comparison of ball velocity in different kicking positions with dominant and non-dominant leg in junior soccer players  [PDF]
MáRIO C. MARQUES,FILIPE PEREIRA,DANIEL A. MARINHO,MAFALDA REIS
Journal of Physical Education and Sport , 2011,
Abstract: Problem Statement: The aim of this study was to compare the ball velocity in different kicking conditions with dominant and non-dominant leg in junior soccer players.Approach: Sixteen junior soccer players (age 17.6±0.6yr, height 1.76±0.06m, and weight 67.9±5.2kg) participated in this study. All participants kicked a soccer ball three times in seven conditions with the dominant and non-dominant leg. 1) Kicking the ball from 11m straight forwards, 2 and 3) kicking the ball from 11m to the left and right side of the goal, 4 and 5) kicking the ball straight forwards from 11m after a pass from the left and right side, 6 and 7) kicking the ball straight forwards from 11m after a pass that came from a diagonal position (45o) from the left and right side. The highest ball velocity was used for analysis.Results: Significant differences were found in ball velocity between the dominant and non-dominant leg in all conditions (p<0.001). For the dominant leg also significant differences were found in the kicking of eleven meters (ideal conditions) compared with: the perpendicular passing kick after the ball on the right (p=0.0024) and left (p=0.0080) and also with a diagonal kick after pass (45 °) of the ball on the right (p=0.0017) and left (p = 0.0381). Significant differences in the kicking with the non-dominant leg were found when kicking from eleven meters to the right side of the goal in comparison to: the kick under the same conditions, to the left side of the goal (p=0.0243) after pass and shot from the left side perpendicular (p=0.0222).Conclusions/Recommendations: kicking velocity is influenced very much under different conditions when kicking with the dominant leg while for the non-dominant leg this influence was small, because the non-dominant leg is less trained, so the values of velocity in different conditions, in addition to being the lowest, are closer than those obtained with the dominant leg
Peptide glutamine supplementation for tolerance of intermittent exercise in soccer players
Favano, Alessandra;Santos-Silva, Paulo Roberto;Nakano, Eduardo Yoshio;Pedrinelli, André;Hernandez, Arnaldo José;Greve, Julia Maria D′Andrea;
Clinics , 2008, DOI: 10.1590/S1807-59322008000100006
Abstract: objective: to investigate whether supplementation of carbohydrate together with peptide glutamine would increase exercise tolerance in soccer players. methods: nine male soccer players (mean age: 18.4 ± 1.1 years; body mass: 69.2 ± 4.6 kg; height: 175.5 ± 7.3 cm; and maximum oxygen consumption of 57.7 ± 4.8 ml.kg-1.min-1) were evaluated. all of them underwent a cardiopulmonary exercise test and followed a protocol that simulated the movements of a soccer game in order to evaluate their tolerance to intermittent exercise. by means of a draw, either carbohydrate with peptide glutamine (carboglut: 50g of maltodextrin + 3.5g of peptide glutamine in 250 ml of water) or carbohydrate alone (carbo: 50g of maltodextrin in 250 ml of water) was administered in order to investigate the enhancement of the soccer players' performances. the solution was given thirty minutes before beginning the test, which was performed twice with a one-week interval between tests. results: a great improvement in the time and distance covered was observed when the athletes consumed the carboglut mixture. total distance covered was 12750 ± 4037m when using carbo, and 15571 ± 4184m when using carboglut (p<0.01); total duration of tolerance was 73 ± 23 min when using carbo and 88 ± 24 min when using carboglut (p<0.01). conclusion: the carboglut mixture was more efficient in increasing the distance covered and the length of time for which intermittent exercise was tolerated. carboglut also reduced feelings of fatigue in the players compared with the use of the carbo mixture alone.
FUNCTIONAL STATUS AND INFLAMMATION AFTER PRESEASON TRAINING PROGRAM IN PROFESSIONAL AND RECREATIONAL SOCCER PLAYERS: A PROTEOMIC APPROACH  [cached]
Francisco J. Martín-Sánchez,José María Villalón,José J. Zamorano-León,Luis Fernández Rosas
Journal of Sports Science and Medicine , 2011,
Abstract: The purpose of the study was to determine if an intensive pre- season training program modifies the inflammatory status in professional soccer players and if this inflammatory profile may be associated with the physical state. We compared plasma protein biomarkers, using proteomics, and the physiological state and cardiac function in 12 professional soccer players and 9 recreational soccer players. Reduced cardiac low frequency [LF] after the pre- season training program previous competition with respect to recreational soccer players was found. No differences were found in cardiac high frequency, cardiac high frequency/low frequency ratio, tension index and oxygen volume consumption. Alpha-1-antitrypsin isotype-3, fibrinogen-gamma isotypes-1, 2 and 3 and vitamin-D-binding protein isotype-1 were reduced in professionals players compared with those in recreational players. However, an increased content of alpha-1-antitrypsin isotype-6 and alpha-1-antichymotrypsin 1 and 4 were found in professional soccer players. Spearman′s analysis showed a positive correlation between LF and fibrinogen-gamma chain isotype 3; but LF was negatively correlated with alpha-antichymotrypsin isotype 4. Professional soccer players submitted to an intensive training showed differences in the content of plasma proteins associated with inflammatory/oxidative stress and thrombosis with respect to recreational soccer players. Proteomics analysis in combination with the analysis of cardiac function assessment may be useful to know more in depth molecular processes associated with sport and intensive exercise.
Iron status in spanish junior soccer and basketball players. Status en hierro de jugadores de fútbol y baloncesto de la categoría junior.  [PDF]
González Gross, Marcela,Sola , Ricardo,Valtue?a , Jara
RICYDE : Revista Internacional de Ciencias del Deporte , 2006,
Abstract: Aim: To assess the dietary iron intake and the iron status of Spanish junior athletes and its importance on performance, and to discuss abount the consequences of an iron deficiency. Material and methods: Forty six soccer and eleven basketball players aged 17-21 years (mean age 18.2 +1.1) who played in the Spanish national junior soccer and basketball league, respectively, who had neither drugs, medicines intake nor illness during the study which altered the appetite or some studies parameters, took part in the study. Dietary intake was assessed by means of a 7-day weighed food intake record. Iron status was evaluated by means of a complete hemogram, serum iron, ferritin, transferrin and TIBC. Results: Mean iron intake was 19.24±4.58 mg/day. Mean analytical data were all between reference ranges. Basketball players had higher intake levels compared with soccer ones (22.1+6.4 and 19.2+3.9 mg/day, respectively; p< 0.05 ). Nevertheless, basketball players had lower levels of mean red blood cells, haemoglobin, hematocrit and the mean corpuscular volumes comparing with soccer players. Conclusions: During adolescence, iron requirements are very high which could place adolescent athletes in a high risk group for iron deficiency and iron deficiency anaemia. In the current research, the population studied shows an acceptable iron status although there are 3% of iron deficiency anaemia cases.Resumen Objetivos: valorar la ingesta diaria y el estatus de hierro de los atletas junior espa oles y su importancia sobre el rendimiento, así como lo que respecta a las consecuencias que tiene una deficiencia de hierro. Material y métodos: cuarenta y seis jugadores de fútbol y once de baloncesto con edades comprendidas entre los 17 y 21 a os (la media de edad 18.2 + 1.1) que jugaban en la liga junior nacional de fútbol y baloncesto, respectivamente, y que no tomaban drogas, medicinas ni presentaban ninguna enfermedad durante el desarrollo del estudio que pudiera alterar el apetito o algunos de los parámetros objeto de estudio, tomaron parte en este estudio. La ingesta dietética se cuantificó mediante la técnica de "registro de consumo de alimentos" durante 7 días consecutivos. El estatus de hierro se evaluó por un completo hemograma, hierro sérico, ferritina, transferritina y TIBC. Resultados: La media de ingesta de hierro fue de 19.74±4.58 mg/día. Los datos analíticos significativos estaban todos entre los rangos de referencia. Los jugadores de baloncesto presentaron una ingesta significativamente superior que los de fútbol (22.1±6.4 y 19.2±3.9 mg/día). Sin embargo
Explosive strength, velocity and specific motor skills in soccer junior players: A correlational study A for a explosiva, velocidade e capacidades motoras específicas em futebolistas juniores amadores: Um estudo correlacional  [cached]
Mário Cardoso Marques,Bruno Travassos,Ruben Almeida
Motricidade , 2010, DOI: 10.6063/motricidade.6(3).140
Abstract: The main aims of the present study were: a) to evaluate speed and technical skills, and b) to examine the relationship between those measures. Thirty-seven junior soccer players under 19 years of age from three amateur soccer teams were evaluated using vertical and horizontal jump tests, 30m sprint speed test, change of direction test, dribble test and the kicking speed test. The significant correlations found help to understand this population's performance. Os objectivos deste estudo foram: i) avaliar os níveis de for a explosiva dos membros inferiores (manifesta o "reflexo – elástico – explosiva"), de velocidade e de capacidades motoras específicas, em futebolistas juniores enquadrados em estruturas desportivas de estatuto n o profissional; e, ii) conferir a rela o entre as valências avaliadas em futebolistas juniores amadores. Trinta e sete futebolistas juniores, pertencentes a três equipas amadoras foram avaliados através do teste de Sargent, salto horizontal, sprint 30 m, mudan a de direc o, drible test e velocidade imprimida à bola no remate. De acordo com os resultados, pode afirmar-se que as significativas correla es verificadas entre distintos movimentos constituem uma "ferramenta" útil para explicar parte do rendimento nesta popula o.
Effect of Maturation on Hemodynamic and Autonomic Control Recovery Following Maximal Running Exercise in Highly Trained Young Soccer Players  [PDF]
Martin Buchheit
Frontiers in Physiology , 2011, DOI: 10.3389/fphys.2011.00069
Abstract: The purpose of this study was to examine the effect of maturation on post-exercise hemodynamic and autonomic responses. Fifty-five highly trained young male soccer players (12–18 years) classified as pre-, circum-, or post-peak height velocity (PHV) performed a graded running test to exhaustion on a treadmill. Before (Pre) and after (5th–10th min, Post) exercise, heart rate (HR), stroke volume (SV), cardiac output (CO), arterial pressure (AP), and total peripheral resistance (TPR) were monitored. Parasympathetic (high frequency [HFRR] of HR variability (HRV) and baroreflex sensitivity [Ln BRS]) and sympathetic activity (low frequency [LFSAP] of systolic AP variability) were estimated. Post-exercise blood lactate [La]b, the HR recovery (HRR) time constant, and parasympathetic reactivation (time-varying HRV analysis) were assessed. In all three groups, exercise resulted in increased HR, CO, AP, and LFSAP (P < 0.001), decreased SV, HFRR, and Ln BRS (all P < 0.001), and no change in TPR (P = 0.98). There was no “maturation × time” interaction for any of the hemodynamic or autonomic variables (all P > 0.22). After exercise, pre-PHV players displayed lower SV, CO, and [La]b, faster HRR and greater parasympathetic reactivation compared with circum- and post-PHV players. Multiple regression analysis showed that lean muscle mass, [La]b, and Pre parasympathetic activity were the strongest predictors of HRR (r2 = 0.62, P < 0.001). While pre-PHV players displayed a faster HRR and greater post-exercise parasympathetic reactivation, maturation had little influence on the hemodynamic and autonomic responses following maximal running exercise. HRR relates to lean muscle mass, blood acidosis, and intrinsic parasympathetic function, with less evident impact of post-exercise autonomic function.
Discrepancy between Exercise Performance, Body Composition, and Sex Steroid Response after a Six-Week Detraining Period in Professional Soccer Players  [PDF]
Nikolaos E. Koundourakis, Nikolaos E. Androulakis, Niki Malliaraki, Christos Tsatsanis, Maria Venihaki, Andrew N. Margioris
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0087803
Abstract: Purpose The aim of this study was to examine the effects of a six-week off-season detraining period on exercise performance, body composition, and on circulating sex steroid levels in soccer players. Methods Fifty-five professional male soccer players, members of two Greek Superleague Teams (Team A, n = 23; Team B, n = 22), participated in the study. The first two weeks of the detraining period the players abstained from any physical activity. The following four weeks, players performed low-intensity (50%–60% of VO2max) aerobic running of 20 to 30 minutes duration three times per week. Exercise performance testing, anthropometry, and blood sampling were performed before and after the six-week experimental period. Results Our data showed that in both teams A and B the six-week detraining period resulted in significant reductions in maximal oxygen consumption (60,31±2,52 vs 57,67±2,54; p<0.001, and 60,47±4,13 vs 58,30±3,88; p<0.001 respectively), squat-jump (39,70±3,32 vs 37,30±3,08; p<0.001, and 41,05±3,34 vs 38,18±3,03; p<0.001 respectively), and countermovement-jump (41,04±3,99 vs 39,13±3,26; p<0.001 and 42,82±3,60 vs 40,09±2,79; p<0.001 respectively), and significant increases in 10-meters sprint (1,74±0,063 vs 1,79±0,064; p<0.001, and 1,73±0,065 vs 1,78±0,072; p<0.001 respectively), 20-meters sprint (3,02±0,05 vs 3,06±0,06; p<0.001, and 3,01±0,066 vs 3,06±0,063; p<0.001 respectively), body fat percentage (Team A; p<0.001, Team B; p<0.001), and body weight (Team A; p<0.001, Team B; p<0.001). Neither team displayed any significant changes in the resting concentrations of total-testosterone, free-testosterone, dehydroepiandrosterone-sulfate, Δ4-androstenedione, estradiol, luteinizing hormone, follicle-stimulating hormone, and prolactin. Furthermore, sex steroids levels did not correlate with exercise performance parameters. Conclusion Our results suggest that the six-week detraining period resulted in a rapid loss of exercise performance adaptations and optimal body composition status, but did not affect sex steroid resting levels. The insignificant changes in sex steroid concentration indicate that these hormones were a non-contributing parameter for the observed negative effects of detraining on exercise performance and body composition.
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