Resumen: The aim of this work was to find evidence of aging of ECG indicators in a population of young adults (52 subjects of age 19 ± 0.6 in 2002). For this purpose, an application which analyzes ECG signals was designed and implemented. The data consist in four different series for each subject of the studied population. Two ECG signals of 5 minute duration (one at rest and one after a mild effort) were taken in 2002 and the exact same procedure was repeated for each subject five years later in 2007. All these electrocardiographic signals were examined by computational techniques in order to extract the RR and QT intervals and the energy content of the T-wave. Next, we have compared all the data using first return maps and measured the data dispersion by evaluating the covariance ellipses. Relations between each of the four data series were studied. The analysis also included the gender and the categorical aspect ¿practicing sport¿.