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1.
Eur J Sport Sci ; 22(3): 360-370, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33413049

RESUMO

This study compared the effects of acute caffeine supplementation (3 mg/kg) administered in the morning and evening on performance-related variables in basketball players. Eleven, national-level, adolescent male basketball players underwent field-based fitness testing on four occasions: morning (10:00) with caffeine ingestion (AMCAFF), morning (10:00) with placebo ingestion (AMPLAC), evening (21:00) with caffeine ingestion (PMCAFF), and evening (21:00) with placebo ingestion (PMPLAC). Fitness testing included of a countermovement jump without arm swing (CMJ), CMJ with arm swing (CMJAS), squat jump (SJ), Lane Agility Drill (LAD), 20-m linear sprint, and Suicide Run with (SRD) and without dribbling (SR). Data were analysed using two-way repeated measures analyses of variance and paired t-tests, with effect sizes (ES) also determined for all pairwise comparisons. Follow-up t-test comparisons revealed that AMCAFF produced small-moderate, significant (p<0.001), improvements in CMJ (ES = 0.51), CMJAS (ES = 0.40), SJ (ES = 0.51), and SR (ES = -0.45) compared to AMPLAC. AMCAFF also produced a moderate, significantly (p<0.001) faster LAD (ES = -0.61) compared to PMCAFF. PMPLAC demonstrated small-moderate, significant (p<0.05) improvements in CMJ (ES = 0.43), CMJAS (ES = 0.48), and 20-m sprint (ES = -0.63) compared to AMPLAC. In contrast, AMPLAC resulted in large, significantly (p<0.001), faster SRD (ES = -1.46) and SR (ES = -1.59) compared to PMPLAC. Given the ergogenic effects of caffeine during basketball-specific fitness tests appear to be influenced by time of ingestion, basketball practitioners should consider administering caffeine only to players in the morning to improve vertical jump, sprinting, and change-of-direction performance, with no beneficial effects observed with caffeine ingestion in the evening.Highlights The effect of caffeine supplementation on basketball-specific performance related variables were mediated by ingestion time in elite, adolescent basketball players.AMCAFF produced small-moderate improvements in vertical jump, change-of-direction, 20-m linear sprint, and repeated-sprint performance compared to AMPLAC while PMCAFF produced trivial differences in each performance-related variable compared to PMPLAC.Comparisons between ingestion times in the placebo condition revealed vertical jump height and 20-m sprint speed were impaired in the morning compared to the evening, but these time-dependent differences were eliminated when caffeine was consumed in the morning.Basketball practitioners should consider administering caffeine only to players in the morning to improve vertical jump, sprinting, and change-of-direction performance, with no beneficial effects observed with caffeine ingestion in the evening.


Assuntos
Desempenho Atlético , Basquetebol , Adolescente , Cafeína/farmacologia , Suplementos Nutricionais , Teste de Esforço , Humanos , Masculino
2.
J Strength Cond Res ; 35(11): 3151-3157, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31403572

RESUMO

ABSTRACT: Stojanovic, E, Stojiljkovic, N, Stankovic, R, Scanlan, AT, Dalbo, VJ, and Milanovic, Z. Recreational basketball small-sided games elicit high-intensity exercise with low perceptual demand. J Strength Cond Res 35(11): 3151-3157, 2021-The purpose of this study was to describe and compare the internal and external load imposed on players during 1-a-side, 2-a-side, and 3-a-side recreational basketball small-sided games (SSGs). Twelve recreationally active, male college students were monitored across 10 minutes of 1-a-side, 2-a-side, and 3-a-side basketball SSG. Internal load variables included continuous measurement of heart rate (HR) responses, as well as rating of perceived exertion (RPE) and blood lactate concentration (BLa), after each game. External load variables included measurement of the total distance covered as well as the frequency of accelerations and decelerations. Blood lactate concentration and RPE were moderately (p < 0.05) greater in 1-a-side SSG than 3-a-side SSG. Total accelerations and decelerations were higher in 1-a-side and 2-a-side SSG compared with 3-a-side SSG (p < 0.05, moderate-large). All SSG formats resulted in players spending more time (p < 0.05, moderate-large) at higher HR intensities (81-100% HRmax) than lower intensities (≤80% HRmax). Furthermore, players covered greater distances (p < 0.05, large-very large) at lower intensities (0-12 km·h-1) and completed more accelerations and decelerations (p < 0.05, large-very large) at lower intensities (<2 m·s-2) than at higher intensities across SSG formats. Basketball SSG consisting of 1-3 players elicits an intermittent activity profile, promoting the extensive utilization of anaerobic and aerobic metabolism pathways, which potentially can lead to marked improvements in cardiovascular and musculoskeletal fitness in the general population when administered in recreational settings. Moreover, recreational basketball SSG with only 1 player per team elicits higher BLa, RPE, distances covered at low speeds as well as acceleration and deceleration volumes than SSG with 3 players per team.


Assuntos
Desempenho Atlético , Basquetebol , Corrida , Aceleração , Desempenho Atlético/fisiologia , Basquetebol/fisiologia , Exercício Físico/fisiologia , Frequência Cardíaca , Humanos , Masculino , Esforço Físico/fisiologia , Corrida/fisiologia
3.
J Exerc Sci Fit ; 19(1): 40-46, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32922462

RESUMO

BACKGROUND: Conditioning in the form of football small-sided games (SSG) is being increasingly utilized as a health-promoting and performance-enhancing activity. OBJECTIVE: The aim of this study was to quantify and compare the physiological responses and activity demands encountered during 3-a-side, 4-a-side, and 5-a-side football SSG in recreational players. METHOD: Heart rate, blood lactate (BLa), rating of perceived exertion (RPE) and activity demands were measured across 2 × 20-min football sessions played on a 40 × 20-m pitch in 12 recreationally active college students. Data were collected over a period of two weeks using a repeated-measures crossover design. RESULTS: Mean heart rate was higher (moderate) during 5-a-side than 4-a-side (p = 0.02) and 3-a-side SSG (p < 0.001). BLa tended to be higher (small) in 3-a-side compared to 4-a-side (p = 0.12) and 5-a-side SSG (p = 0.46). The total distance covered was lower (large) during 5-a-side than 4-a-side SSG (p = 0.02), while the total number of accelerations (p = 0.01) and decelerations (p = 0.02) were higher (large) during 5-a-side than 4-a-side SSG. CONCLUSION: These data suggest: 1) 5-a-side SSG require a greater intermittent workload and exacerbated HR responses; 2) 4-a-side SSG require more sustained activity (distance); and 3) 3-a-side SSG result in higher BLa compared to other SSG formats. The observed intermittent workload and exacerbated HR response in 5-a-side SSG were likely due to greater turnover rates with more frequent interceptions. Sustained activity in 4-a-side SSG might be underpinned by format-specific structures permitting optimal team work, while isolated guarding of players in 3-a-side SSG may have exacerbated BLa responses.

4.
Biol Sport ; 37(1): 69-78, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32205912

RESUMO

The aim of this study was to examine the impact of team size on acute physiological, perceptual, and activity demands of recreational handball to provide a better understanding for the potential prescription of recreational handball to achieve health benefits. Active, male college students (N=22) completed 3-, 4-, and 5-a-side handball game formats across three separate sessions following a repeated-measures, crossover design. Heart rate (HR), blood lactate concentration (BLa), rating of perceived exertion (RPE), distance covered, and frequency of accelerations/decelerations were monitored during games. Each game format elicited vigorous intensities with a mean HR in the range 82-85%HRmax and post-game BLa in the range 3.9-4.4 mmol·L-1. No significant differences (P>0.05) in absolute (ηp2=0.40), relative mean HR (ηp2=0.43), BLa (ηp2=0.16), total distance (ηp2=0.32), total accelerations (ηp2=0.23), or total decelerations (ηp2=0.23) were observed between game formats. A significant effect was observed for RPE (ηp2=0.51), where 3-a-side games elicited a higher RPE than 5-a-side games (P=0.03, large). Modifying player number has a negligible effect on the physiological and activity demands encountered during recreational handball games. Recreational handball consisting of 3-5 players imposes similar intermittent workloads, resulting in vigorous physiological responses concomitant with those recommended for overall health improvements as part of regular training.

5.
Appl Physiol Nutr Metab ; 44(8): 849-856, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30633542

RESUMO

The aim of this study was to determine the effect of acute caffeine supplementation on anaerobic performance in professional female basketball players. A double-blind, placebo-controlled, experimental design was used in a randomized counterbalanced manner. In separate sessions, 10 professional basketball players ingested caffeine (3 mg/kg body mass) or a placebo (dextrose: 3 mg/kg body mass) 60 min before completing countermovement jumps (CMJ) with and without arm swing, a squat jump (SJ), the Lane Agility Drill, 20-m sprints (with 5-m and 10-m split times recorded) with and without dribbling a ball, and a suicide run. Participants provided ratings of perceived exertion (RPE) and ratings of perceived performance 30 min following testing. Data analyses included the use of effect size (ES) and significance. Caffeine supplementation produced small nonsignificant (p > 0.05) increases in CMJ without arm swing (ES = 0.30), CMJ with arm swing (ES = 0.29), SJ (ES = 0.33), and the lane agility drill (ES = -0.27). Caffeine supplementation produced small to moderate significant improvements in 10-m (ES = -0.63; p = 0.05) and 20-m (ES = -0.41; p = 0.04) sprint times without dribbling. Caffeine supplementation promoted a moderate significant reduction in RPE during the test battery (ES = -1.18; p = 0.04) and a small nonsignificant improvement in perceived performance (ES = 0.23; p = 0.53). Acute caffeine supplementation may produce small to moderate improvements in key performance attributes required for basketball while reducing RPE.


Assuntos
Desempenho Atlético , Basquetebol , Cafeína/administração & dosagem , Cafeína/farmacologia , Estimulantes do Sistema Nervoso Central/administração & dosagem , Estimulantes do Sistema Nervoso Central/farmacologia , Adolescente , Método Duplo-Cego , Feminino , Humanos , Corrida , Adulto Jovem
6.
J Strength Cond Res ; 33(11): 3162-3173, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29927890

RESUMO

Stojanovic, E, Aksovic, N, Stojiljkovic, N, Stankovic, R, Scanlan, AT, and Milanovic, Z. Reliability, usefulness, and factorial validity of change-of-direction speed tests in adolescent basketball players. J Strength Cond Res 33(11): 3162-3173, 2019-The purposes of this study were to (1) determine the reliability, usefulness, and factorial validity of change-of-direction speed (CODS) tests in adolescent basketball players and (2) evaluate positional differences in test performances. Elite, adolescent male basketball players (n = 53; 17.3 ± 1.0 years) completed 6 CODS tests: "Lane Arrow Closeout," "Lane Agility Drill," "Reactive Shuttle Test," "Run-Shuffle-Run," "Compass Drill," and "Modified 505 Test." Players completed 3 trials of each test. All tests demonstrated acceptable reliability (intraclass correlation coefficient: 0.50-0.88; coefficient of variation: 5.1-7.9%). The typical error (TE) calculated for each test was above the smallest worthwhile change, rating the usefulness of all tests as marginal. The principal component factor analysis in all tests resulted in the extraction of one significant component that explained 74% of the total variance across tests. Positional comparisons showed that backcourt (guards) players performed better (small to moderate differences) in all CODS tests compared with frontcourt (forwards and centers) players. All tests were deemed reliable and valid in adolescent basketball players. The "Lane Agility Drill" and "Run-Shuffle-Run" tests seem the most appropriate to quantify changes in CODS possessing the lowest TE, whereas the "Lane Arrow Closeout" and "Lane Agility Drill" tests are the most sensitive in detecting positional differences.


Assuntos
Desempenho Atlético , Basquetebol , Teste de Esforço/métodos , Adolescente , Adulto , Humanos , Masculino , Análise de Componente Principal , Reprodutibilidade dos Testes
7.
Int J Sports Physiol Perform ; 14(7): 997-1000, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30569790

RESUMO

PURPOSE: To examine the effect of caffeine supplementation on dribbling speed in elite female and male basketball players. METHODS: A double-blind, counterbalanced, randomized, crossover design was utilized. Elite basketball players (n = 21; female, n = 10; male, n = 11; age = 18.3 ± 3.3 yr) completed placebo (3 mg·kg-1 of body mass of dextrose) and caffeine (3 mg·kg-1 of body mass) trials 1 week apart during the in-season phase. During each trial, players completed 20-m linear sprints with and without dribbling a basketball. Performance times were recorded at 5-m, 10-m, and 20-m splits. Dribbling speed was measured using traditional (total performance time) and novel (Dribble Deficit) methods. Dribble Deficit isolates the added time taken to complete a task when dribbling compared to a non-dribbling version of the same task. Comparisons between placebo and caffeine conditions were conducted at group and individual levels. RESULTS: Non-significant (P > 0.05), trivial-small (effect size = 0.04-0.42) differences in dribbling speed were observed between conditions. The majority (20 out of 21) of players were classified as non-responders to caffeine, with 1 player identified as a negative responder using Dribble Deficit measures. CONCLUSIONS: Results indicate caffeine offers no ergogenic benefit to dribbling speed in elite basketball players. The negative response to caffeine in one player indicates caffeine supplementation may be detrimental to dribbling speed in specific cases and emphasizes the need for individualized analyses in nutrition-based sport science research.


Assuntos
Desempenho Atlético/fisiologia , Basquetebol/fisiologia , Cafeína/administração & dosagem , Substâncias para Melhoria do Desempenho/administração & dosagem , Adolescente , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Masculino , Adulto Jovem
8.
Int. j. morphol ; 32(3): 1036-1042, Sept. 2014. ilus
Artigo em Inglês | LILACS | ID: lil-728307

RESUMO

Given that a volleyball game requires a certain level of individual anthropological characteristics of young volleyball players to successfully act on situational conditions, and that interdisciplinary approach in the science study is the principal methodological orientation, subject of study in the field of sports is the anthropological status. The aim of this study was to analyze the possible differences in spinal lumbar and abdominal muscles isometric potential of prospective male and female. Sample included 42 subjects (15 male and 27 female subjects), male and female volleyball players, the cadet selection of Serbia, aged 14±0.5 years. Isometric muscle potential assessment was conducted using four standardized motor movement tasks, covering the following areas: static contraction of the flexors of the torso, static contraction of the extensors of the torso, static contraction of the left flexor of the torso, and static contraction of the right flexor of the torso. In addition to the descriptive statistics used, as basis statistics, the t-test for independent samples was used, to compare the mean values of parameters measured in two different groups of athletes ­ volleyball players (girls ­ boys). Descriptive indicators of the sample suggest greater values of deep spinal muscles isometric potential with boys in all study variables. Study results gained by the t-test of independent samples indicate that statistically significant difference exists between their mean results in variables of trunk flexor static contractions and trunk extensor static contractions, at the level 0.001. With other two variables, the values indicate that difference between genders is not significant but accidental. The results of this study regarding static contraction of the right and left lateral flexors of the torso show the lack of statistical significance between male and female cadet volleyball players.


Al considerar que un partido de voléibol requiere cierto nivel de características antropológicas individuales de los jóvenes jugadores de voléibol para actuar con éxito en condiciones situacionales, el enfoque interdisciplinario principal en el estudio de las ciencias del deporte es la orientación metodológica, como también lo es el estado antropológico de los jugadores. El objetivo de este estudio fue analizar las posibles diferencias en la columna lumbar y el potencial isométrico en los músculos abdominales masculinos y femeninos. En la muestra fueron incluidos 42 sujetos (15 varones y 27 mujeres) jugadores de voléibol masculino y femenino de la selección cadete de Serbia, de 14±0,5 años. Se realizó evaluación del potencial muscular utilizando cuatro tareas de movimiento de motor estandarizados en las siguientes áreas: la contracción estática de los flexores del torso, de contracción estática de los extensores del tronco, contracción estática del flexor izquierdo del torso, y la contracción estática del flexor derecho del torso. Además de las estadísticas descriptivas y las estadísticas de base utilizadas, se usó la prueba t para las muestras independientes para comparar los valores medios de los parámetros medidos en dos grupos diferentes de los deportistas - jugadores de voléibol (niñas - niños). Los indicadores descriptivos de la muestra sugieren mayores valores de potencial isométrico de los músculos espinales profundos en niños en todas las variables del estudio. Los resultados del estudio obtenidos por la prueba t de muestras independientes indicaron que existe una diferencia estadísticamente significativa entre los resultados medios en las variables de los flexores del tronco y en las contracciones estáticas de los extensores del tronco, en el nivel de 0,001. Con otras dos variables, los valores indicaron que la diferencia entre ambos sexos no es significativa pero es accidental. Los resultados de este estudio con respecto a la contracción estática del lado derecho y flexores laterales izquierdos del torso muestran la falta de significación estadística entre los jugadores masculinos y femeninos de voléibol.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Força Muscular/fisiologia , Voleibol , Tronco/fisiologia , Estudos Transversais , Caracteres Sexuais , Contração Isométrica
9.
J Strength Cond Res ; 26(6): 1475-80, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21904244

RESUMO

The purpose of this study was to determine the changes in physical performance after a 6-week skill-based conditioning training program in male competitive volleyball players. Sixteen male volleyball players (mean ± SD: age 22.3 ± 3.7 years, body height 190.7 ± 4.2 cm, and body mass 78.4 ± 4.5 kg) participated in this study. The players were tested for sprinting (5- and 10-m sprint), agility, and jumping performance (the vertical-jump test, the spike-jump test, and the standing broad jump [SBJ]). Compared with pretraining, there was a significant improvement in the 5- and 10-m speed. There were no significant differences between pretraining and posttraining for lower-body muscular power (vertical-jump height, spike-jump height, and SBJ) and agility. Based on our results, it could be concluded that a preseason skill-based conditioning program does not offer a sufficient stimulus for volleyball players. Therefore, a general conditioning and hypertrophy training along with specific volleyball conditioning is necessary in the preseason period for the development of the lower-body strength, agility and speed performance in volleyball players.


Assuntos
Desempenho Atlético/fisiologia , Força Muscular/fisiologia , Educação Física e Treinamento , Aptidão Física/fisiologia , Voleibol/fisiologia , Exercício Físico/fisiologia , Humanos , Estudos Longitudinais , Masculino , Músculo Esquelético , Corrida
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