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Indexed/Abstracted in: Chemical Abstracts, CINAHL, Current Contents/Clinical Medicine, EMBASE, PubMed/MEDLINE, Science Citation Index Expanded (SciSearch), Scopus
Impact Factor 1,111
Online ISSN 1827-1928
Darby L. A., Yaekle B. C.
Exercise Physiology Laboratory, School of Human Movement, Sport and Leisure Studies, Bowling Green State University, Bowling Green, Ohio, USA
Background. The purpose of this study was to compare heart rate (HR) and oxygen consumption (V.O2) for similar upright exercises performed on land (LN) and in water (WA).
Methods. Setting and participants: apparently healthy, females (n=12; 20.0±1.6 yrs) completed legs only, and arms and legs exercises in WA (30.0±0.0 C) and LN (27.3±2.1 C). Intervention: exercise cadence/intensity increased each 3 min to evoke comparable, relative exercise HRs on LN and WA for each participant. Experimental design: three-way (Environment X Type of exercise X Intensity) repeated measures ANCOVAs with pace as the covariate were calculated for V.O2 and HR. Linear and multiple regressions were determined. Measures: HR, V.O2, and pace were measured for the final steady state minute of all levels of the independent variables. Resting HR and blood pressure were measured pre- and postexercise.
Results. There was a significant main effect due to environment for V.O2. There was not a significant main effect of environment for HR because the pace of exercise was adjusted in the water so that similar “relative” workloads (i.e., intensities, assessed from monitoring HR) were given to each participant. HR and V.O2 were greater for arms and legs exercise, and were greater at increased exercise intensities. No interactions were present among the independent variables. When WA exercise was performed at HR levels comparable to HR during land exercise, WA V.O2 were 2-6 ml.kg-1.min-1 greater than LN V.O2. Conclusions. Participants were at a >V.O2 in WA, but would not know this from monitoring their HRtraining. During WA exercise, the HR-V.O2 regression line was shifted to the right. Results of the regression analyses showed that V.O2 was a significant predictor of HR. HRtraining predicted using these equations indicated that HRtraining during upright water exercise should be decreased by approximately 7-13 beats.min-1 for legs only water exercise and arms/legs water exercise to attain intensities comparable to LN exercise.