Maximal Physiological Responses between Aquatic and Land Exercise in Overweight Women

Abstract

To investigate the maximal physiological responses between aquatic and land-based graded exercise tests in overweight women. Twenty healthy, overweight (body mass index (BMI) > or = 25 kg.m(-2)), Caucasian women (mean +/- SD; age 48 +/- 7 yr, BMI 30 +/- 4 kg.m(-2)) completed a deep water running (DWR) and treadmill walking (TMW) graded exercise test. Maximal responses during the DWR and TMW graded exercise tests were compared using paired t-tests. Comparisons were made in the incidence of achievement of maximal oxygen consumption (VO2max) criteria between DWR and TMW protocols. Criteria were a plateau in VO2 (change < 2.1 mL.kg.min(-1)), heart rate (HR) equal to or above the age-adjusted maximum, and respiratory exchange ratio (RER) > or = 1.15. Maximal responses for VO2max (22.5 +/- 4.86 vs 27.7 +/- 4.73 mL.kg.min(-1)), HRmax (159 +/- 16 vs 170 +/- 12 bpm), and RER (1.03 +/- 0.06 vs 1.10 +/- 0.06) were significantly lower (P < 0.01) for the DWR test compared with the TMW test, respectively. Achievement of various VO2max criteria was demonstrated more consistently during the TMW test than the DWR test. Maximal physiological responses of overweight women to DWR and TMW are significantly different but are comparable with other populations. As the maximal responses for DWR compared with TMW differ, the use of land-based criteria for VO2max is not recommended for a graded DWR exercise test.