Effects of acute physical exercise on executive functions: a comparison between aerobic and strength exercise.

The aim of this study was to compare the effects of acute aerobic and strength exercises on selected executive functions. A counterbalanced, crossover, randomized trial was performed. Forty-two healthy women were randomly submitted to three different conditions: (1) aerobic exercise, (2) strength exercise, and (3) control condition. Before and after each condition, executive functions were measured by the Stroop Test and the Trail Making Test. Following the aerobic and strength sessions, the time to complete the Stroop "non-color word" and "color word" condition was lower when compared with that of the control session. The performance in the Trail Making Test was unchanged. In conclusion, both acute aerobic and strength exercises improve the executive functions. Nevertheless, this positive effect seems to be task and executive function dependent.

Desenvolvimento de um método de familiarização individualizado para saltos verticais / Development of an individualized familiarization method for vertical jumps

OBJETIVO: Propor um método de familiarização individualizado para saltos verticais e verificar o seu efeito na variabilidade intrassujeito. MÉTODOS: Cinquenta e três homes (média ± DP; idade 23,5 ± 3,3 anos; estatura 1,76 ± 0,08 m; massa 72,8 ± 8,6 kg; percentual de gordura 12,9 ± 5,2%) realizaram sucessivos saltos até atingir o nível de estabilidade proposto. Após 48 h este processo era repetido e a estabilidade entre dias era verificada, se necessário, mais sessões eram realizadas. O nível de estabilidade foi determinado por um teste z, com intervalo de confiança de 95%. Após o processo de familiarização, duas sessões experimentais adicionais foram realizadas para determinar a confiabilidade do desempenho no salto agachado (SA) e no salto com contramovimento (SCM). O coeficiente de variação e o erro padrão de medida foram determinados individualmente (CVi e EPMi). Um teste t pareado foi realizado para verificar diferenças no CVi e EPMi antes e depois do processo de familiarização. RESULTADOS: O CVi apresentou uma redução significativa após o processo de familiarização (p < 0,001), alterando de 5,01 ± 2,40% para 2,95 ± 0,89% no SA e de 4,50 ± 2,19% para 2,58 ± 0,81% no SCM. O mesmo ocorreu para o EPMi variando de 1,29± 0,53 cm para 0,83 ± 0,25 cm no SA e de 1,35 ± 0,51 cm para 0,83 ± 0,26 cm no SCM. CONCLUSÃO: o método de familiarização individualizado proposto reduziu significativamente a variação intrassujeito, permitindo maior poder estatístico em estudos experimentais e maior sensibilidade para ferramentas de monitoramento do desempenho.

OBJECTIVE: The aim of the present study was to propose an individualized familiarization method for vertical jumps and to verify its effect on intra-subject variability. METHODS: Fifty three men (mean ± S.D.; age 23.5 ± 3.3; height 1.76 ± 0.08 m; mass 72.8 ± 8.6 Kg; body fat 12.9 ± 5.2%) performed successive jumps to reach the proposed stability level. After 48 hours, this process was repeated and the stability between the days was verified; if necessary, more sessions were performed. The stability level was determined by a Z-Test with a confidence interval of 95%. After the familiarization process, two additional experimental sessions were performed in order to determine the reliability of the performance in the Squat Jump (SJ) and the Countermovement Jump (CMJ). The coefficient of variation and standard error of measurement were determined individually (CVi and SEMi). A paired T-Test was performed to verify differences in the CVi and SEMi before and after the familiarization process. RESULTS: The CVi presented a significant reduction after the familiarization process (p < 0.001), changing from 5.01 ± 2.40% to 2.95 ± 0.89% in the SJ. The CVi also changed in the CMJ (from 4.50 ± 2.19% to 2.58 ± 0.81%). The same also occurred with the SEMi in both the SJ and the CMJ, changing from 1.29 ± 0.53 cm to 0.83 ± 0.25 cm in the SJ and from 1.35 ± 0.51cm to 0.83 ± 0.26 cm in the CMJ. CONCLUSION: The proposed individualized familiarization method significantly decreased intra-subject variability, which allows for a higher statistical power in the laboratorial setting and a greater sensitivity for performance monitoring tools.