Six weeks of aerobic training improves VO2max and MLSS but does not improve the time to fatigue at the MLSS.

The purpose of this study was to investigate the effects of a 6-week aerobic training period on the time to fatigue (t lim) during exercise performed at the maximal lactate steady state (MLSS). Thirteen untrained male subjects (TG; age 22.5 ± 2.4 years, body mass 72.9 ± 6.7 kg and VO2max 44.9 ± 4.8 mL kg(-1) min(-1)) performed a cycle ergometer test until fatigue at the MLSS power output before and after 6 weeks of aerobic training. A group of eight control subjects (CG; age 25.1 ± 2.4 years, body mass 70.1 ± 9.8 kg and VO2max 45.2 ± 4.1 mL kg(-1) min(-1)) also performed the two tests but did not train during the 6-week period. There were no differences between the groups with respect to the VO2max or MLSS power output (MLSSw) before the treatment period. The VO2max and the MLSSw of the TG increased by 11.2 ± 7.2 % (pre-treatment = 44.9 ± 4.8 vs. post-treatment = 49.8 ± 4.5 mL kg(-1) min(-1)) and 14.7 ± 8.9 % (pre-treatment = 150 ± 27 vs. post-treatment = 171 ± 26 W), respectively, after 6 weeks of training. The results of the CG were unchanged. There were no differences in t lim between the groups or within groups before and after training. Six weeks of aerobic training increases MLSSw and VO2max, but it does not alter the t lim at the MLSS.

Limiar anaeróbio de jogadores de futebol de diferentes categorias / Anaerobic threshold in different categories of soccer players

Diferentes variáveis podem ser utilizadas para a identificação e monitoramento da capacidade aeróbia em esportes coletivos, sendo o limiar anaeróbio (LAN) muito utilizado em atividades como futebol, basquete, handebol entre outros. O objetivo do estudo foi determinar a intensidade do LAN de jogadores de futebol de diferentes categorias, avaliando os parâmetros velocidade, freqüência cardíaca (FC) e percentual da FC máxima (%FCmáx), bem como comparar estasintensidades entre as categorias. Participaram do estudo 19 jogadores da categoria sub-17, 12 jogadores Sub-20 e 14 profissionais. O LAN foi determinado a partir da intensidade de 4mM obtida em um teste de campo. Este consistiu em corridas de 1000m, em velocidades constantes a cada tentativa. A FC e lactato ([Lactato]) obtidos no teste foram analisados através de interpolação linear. Foram determinados a velocidade, a FC e %FCmáx correspondentes à intensidade do LAN. Identificou-se que a FCmáx dos jogadores Sub-17 (202 ± 7bpm) foi maior quando comparada àcategoria Profissional (193 ± 10bpm) (p<0,05). O LAN expresso em %FCmáx dos jogadores Sub-17 (87,0 ± 1,1) e Sub-20 (86,3 ± 0,8) foi menor quando comparado à categoria Profissional (91,2 ± 1,1) (p<0,05). A intensidade média do LAN foi 87% FCmáx. Não foram identificadas diferenças entre as categorias quando o LAN foi considerado em bpm e como velocidade de corrida. Concluiu-se que a intensidade do LAN neste grupo pode ser considerada alta, sendo que os jogadores profissionaisapresentam LAN mais alto em comparação com as categorias Sub-17 e Sub-20.

Different variables can be used for the identification and monitoring ofaerobic capacity in collective sports, with the anaerobic threshold (AT) being commonly used in long-duration team sports such as soccer, basketball, and handball. The aim of this study was to determine AT intensity in different categories of soccer players by evaluating running speed, heart rate (HR) and percent maximum HR (%HRmax), and to compare these intensities between three soccer categories. Nineteen U-17, 12 U-20 and 14 professional players volunteered for this study. The AT was defined as the exercise intensity at which blood lactate reaches a concentration of 4 mM (OBLA). AT was determined in a test consisting of two to five 1000-m runs at constant speed. HR and blood lactate concentration recorded during the test were analyzed bylinear interpolation. The running speed, HR and %HRmax at OBLA were determined. HRmax was higher in U-17 players (202 ± 7 bpm) than in professional players (193 ± 10 bpm) (p<0.05). AT expressed as %HRmax was lower in the U-17 (87.0 ± 1.1) and U-20 (86.3 ± 0.8) categories when compared to the professional category (91.2 ± 1.1) (p<0.05). Mean AT was 87% HRmax. No differences between categories were observedwhen AT was expressed as absolute HR values (bpm) or running speed. The intensity of AT is considered to be high in this group, with professional players presenting a higher AT than U-17 and U-20 players.