Ischemic preconditioning delays the time of exhaustion in cycling performance during the early but not in the late phase

Aims: To investigate the early and late ischemic preconditioning (IPC) effect on the trained cyclists' performance during incremental cycling test until exhaustion. Methods: Twenty-one male cyclists allocated to an IPC (2 x 5-min of blood flow occlusion at 50 mm Hg above systolic pressure followed + 5-min of deflation), SHAM (2 x 5-min at 20 mm Hg) or control (CON; no occlusion) interventions, performed three incremental cycling test (ICT) until exhaustion on separate days. The ICT were conducted pre interventions (baseline), 5-min and 24-h after interventions. The heart rate (HR) and power output (PO) were recorded during all ICT. Results: The IPC group increased ICT performance (4.4 ± 4.0 %; effect size (ES) = 0.27) 5-min post intervention, accompanied by HR mean reduction, compared to baseline (p < 0.05). However, there were no changes in SHAM (2.2 ± 4.2%; ES = 0.07) and CON (2.9 ± 5.0%; ES = 0.06) groups. In 24-h post intervention, SHAM (0.2 ± 4.7%; ES = 0.02) and CON (-1.0 ±1.6; ES = 0.03) maintained (p > 0.05) and IPC group decreased the performance (-4.6 ± 3.6 %; ES = 0.16) compared to 5-min post intervention (p < 0.05), but all groups were similar to baseline (p > 0.05). There were no difference (p > 0.05) among groups for PO peak, HR and ICT performance in all moments (baseline, 5-min and 24-h post intervention). Conclusion: The IPC increases early but not late incremental cycling test performance.(AU)

Testes físicos discriminam praticantes de brazilian jiu-jitsu? / Physical tests discriminate Brazilian Jiu-Jitsu practioners?

Os objetivos deste estudo foram comparar praticantes de Brazilian Jiu-Jitsu (BJJ) experientes (EX) com iniciantes (IN) em relação às resistências de força dinâmica e isométrica, força isométrica máxima e potência aeróbia máxima (VO2max), bem como verificar correlações entre testes. Vinte e oito praticantes de BJJ foram selecionados e divididos em dois grupos: EX (N = 14; 33,8 ± 5,6 anos; faixa roxa até preta; 6,5 ± 5,6 anos de treino em BJJ) e IN (N = 14; 30 ± 2,9 anos; faixa branca; 0,6 ± 0,4 ano de prática de BJJ). Os voluntários realizaram testes, preensão manual (dinamômetro), tempo máximo de sustentação (TMS) e número máximo de repetições (NMR), os dois últimos realizados na barra com pegada no quimono, e teste de 1600 m para determinação indireta do VO2max; com os quais já estavam familiarizados, respeitando as pausas adequadas. Os testes t de Student para amostras independentes e correlação linear de Pearson foram utilizados na análise estatística com significância de 0,05. Os resultados mostraram que apenas o TMS foi significativamente diferente entre os grupos (p < 0,05) e que não houve correlação entre os diferentes testes realizados. Assim, concluímos que a experiência específica em BJJ (tempo de prática e classificação das faixas) influencia apenas a capacidade de resistência de força isométrica e essa valência, portanto, parece ser especial para discriminar diferentes níveis de praticantes de BJJ. Além disso, não há correlações significativas entre os testes investigados neste trabalho.

The aims of this study were to compare Brazilian Jiu-Jitsu (BJJ) experienced practitioners (EX) with beginners (IN) in relation to isometric and dynamic endurance strength, isometric maximal strength and maximal aerobic power (VO2max) and to examine correlations between tests as well. Twenty-eight BJJ practitioners were selected and divided into two groups: EX (N = 14, 33.8 ± 5.6 years; purple to Black belt, 6.5 ± 5.6 years of training in BJJ) and IN (N = 14, 30 ± 2.9 years; white belt, 0.6 ± 0.4 years of practicing BJJ). The volunteers performed tests, handgrip (dynamometer), maximum static lift (MSL) and maximum number of repetitions (MNR), the last two were conducted holding on kimono rolled around the bar, and 1600 m test for indirect determination of VO2max; which they were already familiar with, and appropriate pauses were respected. The t-tests of Student for independent samples and linear correlation of Pearson were used for statistical analysis with significance level of 0.05. The results showed that only the MSL was significantly different between groups (p <0.05) and no correlation between the different tests performed. Thus, we conclude that the specific experience in BJJ (practice time and graduations level) only influences the endurance of isometric strength and this valence, therefore, seems particularly to discriminate different levels of BJJ practitioners. Furthermore, there were no significant correlations between the tests investigated in this work.