Article

The purpose of this study was to compare heart rate (HR) and oxygen consumption (VO2) 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 (273+/-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 VO2 and HR. Linear and multiple regressions were determined. Measures: HR, VO2, 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 VO2. 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 (ie., intensities, assessed from monitoring HR) were given to each participant. HR and VO2 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 VO2 were 2-6 ml.kg(-1).min(-1) greater than LN VO2. CONCLUSIONS: Participants were at a >VO2 in WA, but would not know this from monitoring their HRtraining. During WA exercise, the HR-VO2 regression line was shifted to the right. Results of the regression analyses showed that VO2 was a significant predictor of HR. HRtraning 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.

Langue : ANGLAIS

Tiré à part : OUI

Identifiant basis : 2001216290