Cardiorespiratory responses of healthy subjects to calisthenics performed on land versus in water

Physical Therapy Graduate Program, College of Medicine, University of Iowa, Iowa City 52242.

This study evaluated the oxygen consumption (VO2) and heart rate response curves for standardized upper- and lower-extremity exercise on land and in water. Forty healthy subjects performed one upper-extremity and one lower-extremity exercise at three selected cadences on land and in water. Steady-state heart rate was determined by electrocardiographic radiotelemetry and expressed as a percentage of age-predicted maximal heart rate (% APMHR). Percentage of age-predicted maximal heart rate was used as the criterion measure of relative exercise intensity. Oxygen consumption was determined by the open-circuit method. Results indicated systematic increases in VO2 from 2 to 9 metabolic equivalents (METs) (1 MET = 3.5 mL O2.kg-1.min-1) and % APMHR from 45% to 73% with increased cadence. The VO2 responses were highest during water exercise, whereas % APMHR was greater during land exercise. Based on the magnitude of the responses, water calisthenics appear to be of sufficient intensity to elicit training adaptations. Training studies are needed to document these changes.