RESUMO
The aim of this study was to investigate the autonomic cardiac modulation between professional volleyball players (VP) and recreational aerobically trained individuals (RAT). Methods: Twenty eight men were divided into two groups, (VP; n = 14) and (RAT; n = 14) and each group was subjected to a sub-maximal progressive ramp treadmill test. Cardiac cycle beat to beat (RR) intervals, was obtained through electrocardiogram recording with the test being stopped when the individual reached 85% of their maximum age-predicted heart rate (HR). The heart rate variables were calculated from ECG using MATLAB based algorithms. Results: At rest, RAT showed lower values of the mean value of RR interval, the root mean square successive difference of all RR intervals (r-MSSD), low frequency (LF) and total power spectral (TP) when compared to VP. No significant difference between groups was noted for high frequency (HF) and index LF/HF. After exercise, no significant differences were measured between groups. Mean values of VO2, VE/VO2, and VE showed no significant difference at rest and post effort. Conclusion:The variables such as frequency, intensity and volume may to interfere the autonomic cardiac modulation and possibly indicating a superior protection against exercise-induced ventricular arrhythmias and lower risk of sudden cardiac deaths...
O objetivo do presente estudo foi investigar o perfil da modulação autonômica cardíaca entre jogadores profissionais de voleibol (VP) e indivíduos aerobicamente treinados recreativas (RAT). Métodos: Vinte e oito homens foram divididos em dois grupos (VP; n = 14) e (RAT, n = 14). Cada grupo foi submetido a um teste ergométrico sub-máximo. O teste foi interrompido quando o indivíduo atingiu 85% da frequência cardíaca máxima baseada na idade (HR). Os intervalos R-R foram obtidos através da derivação V5 do eletrocardiograma de 12 derivações. As variáveis de domínio de tempo e frequência da variabilidade da freqüência cardíaca foram calculados utilizando algoritmos baseados em MATLAB. Resultados:Em repouso, RAT apresentaram valores signficativamente reduzidos de intervalo RR, RMSSD, potência espectral de baixa freqüência (LF) e potência espectral total (PT) em relação ao VP. Não houve diferença significativa inter-grupos para potência espectral de alta freqüência (HF) e índice LF/HF. Após o exercício, não foram observadas diferenças significativas inter-grupos. Os valores médios de VO2, VE/ VO2 e VE não apresentaram diferença significativa em repouso e pós esforço inter-grupos. Conclusão: As variáveis como a freqüência, intensidade e volume de treinamento pode interferir na modulação autonômica cardíaca e, possivelmente, indicando uma proteção contra arritmias ventriculares induzidas pelo exercício e menor risco de morte súbita cardíaca...
Assuntos
Humanos , Masculino , Atividade Motora , Atletas , Exercício FísicoRESUMO
The aim of this study was to compare the influence of including dropset exercises in different orders, both in the pre-exhaustion, as in the post-exhaustion method, and to analyze the performance of total work on the bench press and chest flying exercise. Twenty-two male volunteers with a recreational experience in ST were evaluated in six visits in non-consecutive days, at approximately the same time of the day. During the first visit, subjects signed an informed consent form and underwent an anthropometric evaluation and testing of 10RM. The second visit involved a re-test of 10RM. From third to sixth visits, the subjects were randomly grouped into the following experimental situations: 3rd Visit (V3 - Post-exhaustion): Bench Press (dropset) + Chest Flying (10RM); 4th visit (V4 - Post-exhaustion): Bench Press (10RM) + Chest Flying (dropset); 5th Visit (V5 - pre-exhaustion): Chest Flying (dropset) + Bench Press (10RM); 6th Visit (V6 - pre-exhaustion): Chest Flying (10RM) + Bench Press (dropset). The protocol of dropset was performed with 3 sets and no rest intervals 10RM + 80% 10RM + 60% 10RM. An interval between sets was adopted for 2 minutes. The primary results showed a significant difference in Total Work for visits V3 and V6, which was included in the dropset multiarticular exercises. These results suggest that the exercise order with the dropset method in the pre-exhaustion or post-exhaustion methods had an acute influence on Total Work.