Purpose: Peak and maximal oxygen uptake (VO[subscript 2peak] and VO[subscript 2max], respectively) are used in assessing aerobic power. For swimmers with physical impairments, it is unclear whether the physiological variables obtained in 200-m and Nx200-m tests are similar. The objective of this study is to assess the validity of VO[subscript 2peak] as an estimator of VO[subscript 2max] and complementary physiological variables, in particular, carbon dioxide production (VCO[subscript 2]), respiratory exchange ratio (RER), minute-ventilation (V[subscript E] and absolute (HR) and relative (%HRmax) heart rates--which were obtained in a time trial test (200-m) and an incremental intermittent test (Nx200-m) performed by swimmers with physical impairments. Methods: Eleven well-trained swimmers with physical impairments performed 200-m all-out and Nx200-m from low to all-out (controlled by a visual pacer), both with a respiratory valve system and a portable gas analyzer. Results: A paired Student's t-test showed no statistical difference (p > 0.05) for all comparisons. The intraclass correlation coefficient (ICC) was 0.97 and 0.98 for VO[subscript 2] in l/min and ml/kg/min, respectively; ICC = 0.75 to 0.9 for VCO[subscript 2] (l/min and ml/kg/min), V[subscript E] (in l/min) and HR (beats/min); ICC = 0.5 and 0.75 for %HRmax; and ICC < 0.5 for RER. Passing-Bablok regression showed that the dispersions were acceptable, considering the proportionality, except for HR and %HRmax. Bland-Altman method showed a high level of agreement for all variables. Conclusions: The VO[subscript 2peak] and VO[subscript 2max], as well as the physiological variables VCO[subscript 2] and HR obtained, respectively, by 200-m and Nx200-m tests in swimmers with physical impairment were not different.