Associate Professor University of Southern California Los Angeles, California, United States
Abstract Details: Heart rate (HR) is a commonly used method for monitoring the intensity of exercise; however, there can exist a disparity between how an individual perceives their exertion versus how their body is responding to an exercise bout (i.e., HR response). Purpose: To examine how individuals perceived their exertion versus their measured HR during high-intensity interval training (HIIT) while running on a treadmill and riding a stationary bicycle. Methods: Six participants (2 female, 4 male; 28.3 ± 2.1 years), whom did not currently perform regular running and cycling, completed a HR maximum (HRmax) test prior to completing their HIIT protocols. The HIIT protocols consisted of 4 minutes of high intensity at 85-95% HRmax followed by 3 minutes of active recovery repeated 4 times (4x4). HR was measured during the exercise bouts using a Polar H10 HR strap and perceived exertion (RPE) was subjectively measured using the Borg 6-20 scale. Participants were randomized to which exercise modality they completed first and had a 1-week washout period between exercise bouts. Data are presented as mean ± SD. Hedge’s g effect sizes and Pearson correlations were calculated. Results: Active period (AP) average HR during the running protocol was 166.0 ± 10.3 beats per minute versus 152.2 ± 19.4 beats per minute during the cycling protocol (g = 0.82). AP average RPE during the running protocol was 14.6 ± 0.6 versus 15.0 ± 1.5 for the cycling protocol (g = 0.32). HR and RPE were moderately correlated in the running protocol (r = 0.66) and poorly correlated in the cycling protocol (r = 0.38). Conclusions: Different modalities of exercise present unique challenges to exercisers, particularly when the modality is novel to the individual. This study demonstrated large effects between participants’ HR response but smaller effects between subjective RPE ratings. These data are part of a larger ongoing study. Practical Applications: Care should be taken when prescribing exercise programs based solely on RPE which appears to be less sensitive to exercise modality differences compared to HR intensity.