Maximal and ventilatory thresholds cardiorespiratory responses to three water aerobic exercises compared with treadmill on land.

The purpose of this study was to compare the cardiorespiratory responses of young women to exercise at the first ventilatory threshold (VT1), the second ventilatory threshold (VT2), and at maximum effort (MAX) between maximal incremental tests performed using water aerobic exercises and a treadmill on land (TL). Twenty women (24.0 ± 2.5 years; 163.3 ± 6.7 cm; 60.0 ± 6.7 kg) underwent 4 maximal tests in randomized order, with a 48-hour interval between tests. Three tests involved performing water aerobic exercises (stationary running, frontal kick, and cross-country skiing) and 1 TL. Oxygen uptake (VO2), ventilation (VE), and heart rate were measured throughout the tests, and their values at the VT1, VT2, and MAX intensities were determined by 3 independent, experienced physiologists. Repeated measures analysis of variance with Bonferroni post hoc tests were used for comparisons between tests (α = 0.05). Heart rate was significantly higher in the TL condition compared with the water aerobic exercises at the VT1 (p = 0.001), VT2 (p < 0.001), and MAX (p < 0.001) intensities. VO2 and VE had similar values across the 4 protocols at the VT1 intensity, but significantly higher values were observed with TL (VO2: p < 0.001; VE: p < 0.001) at the VT2 intensity. At the MAX intensity, VO2 was significantly higher with TL compared with the 3 water aerobic exercises (p < 0.001), whereas no significant differences in VE between the 4 protocols were found. These results suggest that the prescription of water aerobics classes should be based on specific maximal tests for water aerobic exercises. Training intensities could be overestimated if they were based on maximal tests on dry land.