Aim: The aim of the current study was to analyze the heart rate (HR), oxygen uptake (V.O(2)), and percentage of maximal HR (%HR(max)) and V.O(2) (%V.O(2max)) responses to stationary running exercise performed at different cadences on land (LA) and in water (WA).
Methods: The sample comprised 12 apparently healthy women (mean age 22.33+/-0.57 years). The exercise was performed in WA and LA environments (interval of 2 hours) at submaximal cadences of 60, 80 and 100 bpm for a period of 4 min at each cadence (interval of 5 min). HR and V.O(2) data were collected using a Polar S610TM and Aerosport KB1-C gas analyzer, respectively. The data were analyzed using factorial ANOVA for mixed models, Tukey's post hoc and Pearson's correlation test, with P<0.05 (SPSS version 13.0).
Results: Significant differences were found between the environments for all variables (HR, V.O(2), %HR(max) and %V.O(2max): P<0.001), with higher values for LA. Significant differences were found between the cadences for all variables (HR, V.O(2), %HR(max) and %V.O(2max): P<0.001). The effect of the interaction environment cadence was only significant for %HR(max) (P=0.041). The correlations between HR and V.O(2) (WA: r=0.857; P<0.001 and LA: r=0.556; P<0.001) and %HR(max) and %V.O(2) (WA: r=0.860; P<0.001 and LA: r=0.798; P<0.001) exhibited high and significant correlation coefficient values, especially for WA, suggesting that variable increased linearly with increases in cadence.
Conclusions: The results suggest that cardiorespiratory responses to stationary running exercise are lower in WA, though they can be maximized by increasing the execution cadence.