Time-course of physiological and biomechanical responses to a single bout of high-volume exercise in recreational cyclists

As participation in ultra-long cycling events grows among recreational athletes, there remains a gap in understanding the physiological and biomechanical responses during prolonged exercise. The aim of this study was to investigate the time-course of physiological and biomechanical responses during high-volume cycling. Ten recreational cyclists (12 [range 4-50] years of experience) participated in a repeated measure cohort study. Participants performed up to 6 h of cycling at ~80% heart rate reserve. Objective and subjective measurements were taken hourly and included pelvis and lower limb motion, power output (PO), cadence, heart rate (HR) and rating of perceived exertion (RPE). Data were compared between the Start, Mid and End time points. No significant changes were observed in pelvic or lower limb joint angles. HR, PO, cadence and work remained stable. However, RPE increased significantly from Start to Mid (<i>p</i> = 0.02, d = 1.59) and Start to End (<i>p</i> < 0.01, d = 2.37), indicating large increases in perceived exertion. Recreational cyclists maintained consistent pelvic and lower limb biomechanics during 6 h of high-volume cycling. These findings suggest movement profile is preserved even as subjective exertion intensifies, indicating that fatigue did not interfere with cycling performance.