The aim of this study was to verify the respiratory muscle strength (RMS) of healthy adolescents, and compare it with predicted normal values. It wasevaluated62adolescents, being 48 female and 14 male, average ageof 18.24±0.43 years, by means of the International Physical Activity Questionnaire (IPAQ) and FMR by manovacuometry by measuring Inspiratory Maximum Pressure (PiMáx) and Expiratory (PeMáx). Data were analyzed by Mann Whitney's t test, unpaired t-test and chi-square test. Regarding the IPAQ, 13 individuals were insufficiently active, 31 active and 18 very active. The values of RMS were different from those predicted, being observed by the increase in the mean of the female PiMáx and the reduction in the male, in addition to the decrease of the PeMáx in both sexes. It was verified that the sample presented RMS impairment, which can impact on the health of this population, being a warning sign, besides recommending future analyzes of the predicted values established.