Author(s): BAI, J., WANG, G., YU, J., LIU, J., GUAN, Y., ZHOU, Y., LIU, Z., YU, Q., Institution: BEIJING RESEARCH INSTITUTE OF SPORTS SCIENCE, Country: CHINA, Abstract-ID: 526

INTRODUCTION:
In road cycling training and racing, uphill riding is a critical determinant of performance. Athletes dynamically adjust their cycling posture—primarily between seated and standing positions—based on the gradient, physical fitness, and fatigue when uphill riding. This study aimed to evaluate the gas metabolic characteristics of seated and standing postures across various inclines to optimize cycling strategies and enhance climbing economy.
METHODS:
Eleven male youth cyclists (Age: 17.0 ± 1.1 years; Height: 178.5 ± 4.2 cm; Weight: 71.7 ± 3.5 kg; Body Fat: 16.6 ± 2.7%; Training Experience: 3.4 ± 2.2 years; Relative VO2max: 60.7 ± 2.9 ml/min/kg) were recruited. After determining individual VO2max via an incremental exercise test, subjects performed cycling trials on a cycling treadmill（Rodby Treadmill RL3500）at a constant intensity of 80% VO2max power (monitored via SRM power meters). Trials were conducted at four gradients (0%, 4%, 8%, and 10%) using both seated and standing postures. Gas metabolism (COSMED-K5), blood lactate (Lactate Scout), heart rate (Polar), and Rating of Perceived Exertion (RPE) were recorded. Data were analyzed using paired samples t-tests for RPE and one-way ANOVA for physiological indices, with Cohen’s d calculating effect sizes.
RESULTS:
Oxygen Consumption (VO2): At an 8% gradient, standing cycling showed a significantly lower VO2 (3537.45 ± 442.66 ml/min) compared to seated cycling (3976.53 ± 372.32 ml/min, p < 0.01). No significant differences were observed at other gradients.
Carbon Dioxide Output (VCO2): At 8% gradient, VCO2 was significantly lower in the standing posture (3376.94 ± 534.89 ml/min) than in the seated posture (3755.70 ± 455.91 ml/min, p < 0.05).
Relative VO2: At 8% gradient, relative VO2 was significantly lower during standing (51.45 ± 7.17 ml/min/kg) than seated (57.74 ± 5.20 ml/min/kg), demonstrating a large effect size (Cohen’s d = 1.05).
Energy Expenditure (EE): EE was significantly higher in the seated posture at 8% gradient compared to standing (p < 0.01); this gradient represented the maximal disparity in EE between postures.
Oxygen Pulse: Seated cycling exhibited a significantly higher oxygen pulse than standing cycling across 4%, 8%, and 10% gradients (p < 0.05).
Subjective Strain: At 10% gradient, standing cycling elicited significantly higher maximum HR and RPE compared to seated cycling.
CONCLUSION:
At an intensity of 80%VO2max power, standing cycling is more physiological economical than seated cycling at an 8% gradient, as evidenced by significantly lower relative VO2 and energy expenditure. Therefore, athletes may prioritize standing posture at this specific incline to conserve energy. Conversely, at a 10% gradient, the standing posture induces higher cardiovascular and perceived strain, suggesting its potential utility for high-intensity heart rate and fatigue-resistance training.