Effects of age, sex, sweat rate and environmental conditions on heart rate and perceived exertion in indoor cycling

Abstract

BACKGROUND: Indoor cycling sessions are usually guided by heart rate (HR) and rating of perceived exertion (RPE). This study was designed to examine the effects of sex, age, previous experience, use of a HR monitor, estimated sweat rate and room temperature and humidity increases on HR and RPE during indoor cycling sessions. METHODS: Measurements were made in 39 sessions performed by 300 experienced subjects. Sweat rate was categorized as SR1 ≥ 750, SR2 = 400-749 and SR3 < 400 ml; temperature increase as T1 ≤ 0.2, T2 = 0.2°C-1.5 and T3 > 1.5°C; and humidity as H1 ≤ 2, H2 = 2-15 and H3 > 15 percentage points. Mean HR was determined for the sessions and RPE recorded at the start, middle and end of each session. RESULTS: Significant differences in HR were observed between SR1 and SR3 (148.22 ± 12.17 vs 141.73 ± 17.39 bpm; p<0.05) and between T1 and T2 (141.01 ± 16.38 vs 146.95 ± 15.29 bpm; p<0.05). The RPE was lower (p<0.05) for T1 than T2 or T3 in all recordings and for H1 than H2 or H3 at the session start and middle. CONCLUSION: Our results indicate that real (%HRmax) and perceived (RPE) intensity of exercise in an indoor cycling session are influenced by factors such as the estimated sweat rate, or the increase in temperature or relative humidity produced in the cycling room.