To track and analyze physical activity is highly important due to the relationship with people's state of health, by highlighting the need to conduct the study with technology that allows to measure the level of physical activity and the estimation of energy expenditure. This project supports the implementation of three methods by using inertial sensors to estimate energy expenditure indirectly, in order to relate the values obtained with those calculated by the Leger Test in field trials. The results show that the error values for the estimation of energy expenditure are not significantly different in each method. Therefore, it was determined, from a statistical, engineering perspective and from the experience gained with the use of sensors, that the optimal implementation method for estimating energy expenditure is accelerometry.