David, GB, Andrade, LS, Schaun, GZ, and Alberton, CL. HR, V[Combining Dot Above]O2, and RPE relationships in an aquatic incremental maximum test performed by young women. J Strength Cond Res 31(10): 2852–2858, 2017—The purpose of the study was to verify the relationship between oxygen uptake (V[Combining Dot Above]O2), heart rate (HR), rate of perceived exertion (RPE), and cadence (CAD) in an aquatic incremental maximum test performed during a water-based stationary running exercise. The study also verified the best adjustments for these relationships (linear or polynomial). Thirteen young college women (mean ± SD: 23.15 ± 1.72 years, 21.43 ± 2.09 body mass index) participated in the study. They performed an aquatic incremental maximum test during a water-based stationary running exercise. The experimental protocol started at an initial CAD of 80 b·min−1, and it was followed by increases of 10 b·min−1 every minute until exhaustion. V[Combining Dot Above]O2, HR, and RPE were measured along the test. Linear and polynomial regression analysis were performed to determine the relationship among the percentage of peak V[Combining Dot Above]O2 (%V[Combining Dot Above]O2peak), percentage of maximal HR (%HRmax), RPE, and CAD to determine the best adjustment for each analysis (α = 0.05). The polynomial regression showed the best adjustments for all analysis. Data revealed a significant relationship (p < 0.001) between %V[Combining Dot Above]O2peak and %HRmax (r = 0.858), %HRmax and RPE (r = 0.823), and %V[Combining Dot Above]O2peak and RPE (r = 0.871). Regarding the relationship between these above-mentioned variables and CAD, all of them were significant (p < 0.001), with r = 0.848 for CAD and %HRmax, r = 0.877 for CAD and %V[Combining Dot Above]O2peak and r = 0.878 for CAD and RPE. It was concluded that all analyzed variables are associated and their relationships are in a polynomial quadratic form. Based on the findings, instructors may use the positive relationships between %V[Combining Dot Above]O2peak, %HRmax, and RPE to efficiently prescribe water-based training sessions.