摘要:Objective: analyze the agreement of the V̇O2max values estimated by American College of Sports Medicine and Foster equations with direct measure gas analyze in young Brazilian males. The maximal oxygen uptake, as a health indicator and mortality predictor, can be assessed in different ways. The gold standard comprises the direct measurement of exhaled gases, which entails high cost. A more conveniently form can be estimation equations. Materials and methods: this study assessed VO2max of 41 young Brazilian males (21.4 ±2.2 years) by cardiopulmonary exercise test in a treadmill ergometer with a ramp protocol. Bland and Altman analysis was performed to verify the agreement between V̇O2max measured and estimated values by ACSM and Foster equations. Results: the measured VO2max was 52.3 ± 4.9 ml.kg-1.min-1. The difference between the measured V̇O2max and the estimated V̇O2max by the ACSM equation (9.40±3.67) was approximately 7.5 times greater than the difference between the measured V̇O2max and estimated V̇O2max by Foster’s equation (1.25±3.46). Bland Altman graphics shows that only ACSM equation had mean differences that were significantly different from the measured value. Conclusions: the ACSM equation showed not appropriate for during treadmill stress testing young adults in a ramp protocol and Foster equation seems to be a more accurate estimator of V̇O2max for this population, besides showed a bias along the aerobic capacity, trending to overestimates and underestimates V̇O2max of least and most fit people, respectively.