Influences of Exercise Experience and Exercise Settings on Heart Rate Responses During Self-selected Intensity Exercises

“Self-selected intensity” might be an applicable health promotion strategy, and there is evidence to indicate that the range of self-selected intensity corresponds to the American College of Sports Medicine's recommendation while interindividual variability is great. Hence, investigating the determinants influencing the range of self-selected intensity is encouraged. The purpose of the present study was to explore the heart rate (HR) responses in subjects with different exercise experience levels to 20 minutes of continuous running at self-selected intensity in outdoor (field) and indoor (treadmill) settings. Twenty-six male participants were recruited and assigned to either a high exercise experience group (HG) or low exercise experience group (LG). Each participant performed two bouts of running in field and treadmill settings on separate days, and the sequences of the testing were counterbalanced. Data were analyzed by descriptive statistics and 2 × 2 mixed design analysis of variance. The intensity represented in HR reserve in HGfield, HGtreadmill, LGfield and LGtreadmill were 80.55%, 65.24%, 88.49%and 82.91%, respectively. HG had lower HR response than LG in both field and treadmill settings, and all participants had higher HR response in the field setting compared to the treadmill. Additionally, the interaction effect between exercise experience and exercise setting was significant. HG self-selected lower exercise intensities might be due to their better heartbeat perception, and therefore they could tune exercise intensity finely in the self-regulation process. The higher HR response observed in the field setting might relate to more disturbances from being in an outdoor environment. Exercise settings should be taken into account when prescribing exercise programs.