Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Mais filtros

Base de dados
Ano de publicação
Tipo de documento
Intervalo de ano de publicação
1.
J Strength Cond Res ; 35(4): 1110-1118, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30507732

RESUMO

ABSTRACT: Martínez-Cabrera, FI, Núñez-Sánchez, FJ, Losada, J, Otero-Esquina, C, Sánchez, H, and De Hoyo, M. Use of individual relative thresholds to assess acceleration in young soccer players according to initial speed. J Strength Cond Res 35(4): 1110-1118, 2021-The aims of the current study were (a) to analyze the characteristics of acceleration efforts using individual relative thresholds according to the initial speed during official matches in elite young soccer players according to player position and (b) to compare the differences between absolute and relative thresholds in assessing high-intensity acceleration. Player acceleration profiles were assessed using an individual relative threshold based on their acceleration capacity at different initial speeds (standing, 6, 10.8, and 15 km·h-1), and the number of accelerations (>75% of the maximal acceleration) performed during soccer matches was divided into 3 categories attending to the initial speed. (S1 = 0-7 km·h-1; S2 = 7.1-14 km·h-1; and S3 = ≥14.1 km·h-1). Within-group analyses showed that the number of accelerations performed in each category was higher when the effort started from a static or walking position than at moderate- or high-intensity running (S1 > S2 > S3; very likely to almost certain). Between-group analyses revealed substantial differences between some playing positions according to initial speed. In S1 and S3, central defenders had the lowest number of accelerations (likely to almost certain), whereas midfielders had the greatest number of high-intensity accelerations in S1 and S2. There were also substantial differences between the other playing positions (possibly to almost certain). Regarding relative and absolute thresholds (>3 m·s-2), the results showed that absolute threshold overestimated the number of high-intensity accelerations compared with the individual relative threshold in S1 and underestimated the results in S2 and S3 (almost certain). The use of an individual relative threshold to measure acceleration demands allows to distinguish between the numbers of accelerations in function of the initial speed and playing positions. In addition, the absolute acceleration threshold could overestimate or underestimate the acceleration demands in young soccer players as a function of the initial speed. Then, the absolute acceleration thresholds should be taken with caution in the assessment of acceleration activities.


Assuntos
Desempenho Atlético , Corrida , Futebol , Aceleração , Sistemas de Informação Geográfica , Humanos , Caminhada
2.
J Sports Med Phys Fitness ; 58(10): 1403-1411, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28745474

RESUMO

BACKGROUND: Metabolic power and speed running are in the top-10-ranked variables used to quantify the physical demand in soccer matches or training practices. The main purpose of this study was to compare metabolic power (MP) and the traditional approach using speed running during soccer matches in absolute values and in zones of intensity in function of the playing positions. METHODS: Thirty-eight professional soccer players were analyzed during 18 friendly matches from 4 preseasons (N.=300) and divided into 5 groups of playing positions: central defender (CD) (N.=64), wide defender (WD) (N.=55), central midfielder (CM) (N.=58), wide attacker (WA) (N.=70), and attacker (AT) (N.=53). The individual profiles to each playing positions were assessed using MP and speed running approaches. The magnitude of change was substantial when there was a ≥75% likelihood of the effect. The effect size was also calculated using a confidence interval of 90%. RESULTS: In absolute values, CMs and WAs had substantially greater values than did the other positions, with CMs having the highest values in both approaches and an identical relationship between the positions in both approaches. In categories of intensity, medium-low intensity displayed differences between the approaches; the physical demands of ATs and CDs were lower using the traditional approach but were higher than the other playing positions when assessed using MP. No differences were found at low, medium or high intensities. CONCLUSIONS: The MP and energy expenditure reported differences at medium-low intensity compared to the speed running traditional approach between playing positions. However, the other intensities did not report differences compared to the traditional approach in the different playing positions.


Assuntos
Desempenho Atlético , Corrida/fisiologia , Futebol/fisiologia , Acelerometria , Adulto , Metabolismo Energético , Humanos , Masculino , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA