Correlation between rating of perceived exertion and physiological variables during the execution of stationary running in water at different cadences.

The purpose of the present study was to correlate the rating of perceived exertion (RPE) with cardiorespiratory and neuromuscular variables during the execution of stationary running in water at different cadences. The sample consisted of 12 apparently healthy women (age: 22.33 ± 0.57 years). During the assessment session, the subjects performed the stationary running exercise in water at 3 different cadences: 60, 80, and 100 bpm. The heart rate (HR), oxygen uptake (V(O2)), ventilation (Ve), and electromyographic (EMG) signal of the vastus lateralis (VL), biceps femoris (BF), rectus femoris (RF), and semitendinosus (ST) muscles were measured during the exercise, and the overall body RPE was measured immediately following the end. Pearson's linear correlation and multiple linear regression were used, with p < 0.05. The analyses demonstrate a high and significant relationship between RPE and HR (r = 0.65; p < 0.001), RPE and %HR maximal (r = 0.65; p < 0.001), RPE and V(O2) (r = 0.60; p = 0.001), RPE and %V(O2) maximal (r = 0.71; p < 0.001), and RPE and Ve (r = 0.77; p < 0.001). However, there was no relationship between the RPE and the EMGs of the VL, BF, RF, and ST muscles. With regard to the regression, the model was significant (p < 0.001) with an r2 = 0.79, whereas the variables that explained better the RPE were %V(O2) maximal and Ve. Hence, these results suggest an association between the perception of exertion and cardiorespiratory variables, which was not the case with the neuromuscular variables evaluated in this study. Therefore, the Borg scale of RPE can be used when prescribing stationary running exercise in water for young women.