VO₂ Prediction and Cardiorespiratory Responses During Underwater Treadmill Exercise

Abstract

We compared cardiorespiratory responses to exercise on an underwater treadmill (UTM) and land treadmill (LTM) and derived an equation to estimate oxygen consumption (VO₂) during UTM exercise. Fifty-five men and women completed one LTM and five UTM exercise sessions on separate days. The UTM sessions consisted of chest-deep immersion, with 0, 25, 50, 75, and 100% water-jet resistance. All session treadmill velocities increased every 3 min from 53.6 to 187.8 m·min^-1. Cardiorespiratory responses were similar between LTM and UTM when jet resistance for UTM was ≥ 50%. Using multiple regression analysis, weight-relative VO₂ could be estimated as: VO₂ (mLO₂·kg^-1·min^-1) = 0.19248 · height (cm) + 0.17422 · jet resistance (% max) + 0.14092 · velocity (m·min^-1) - 0.12794 · weight (kg) - 27.82849, R²= .82. Our data indicate that similar LTM and UTM cardiorespiratory responses are achievable, and we provide a reasonable estimate of UTM VO₂.

Key words:

• Aerobic exercise
• Aquatic exercise
• Physical activity
• Walking

Additional information

Notes on contributors

Nicholas P. Greene

Funding was provided by HydroWorx International, Inc. The authors thank all the dedicated students of the Applied Exercise Science Laboratory of Texas A&M University for their aid in data collection. In particular, we thank Brad Lambert and Brent Hansen. At the time of this study, the first author was with Texas A&M University. Please address correspondence concerning this article to Nicholas P. Greene, Robert M. Berne Cardiovascular Research Center, 415 Lane Rd., University of Virginia, Charlottesville, VA 22908.