Physiological Demands of Simulated Off-Road Cycling Competition

Area of Science:

• Sports Science
• Exercise Physiology
• Biomechanics

Background:

• Cross-country cycling (COMP) involves high energy expenditure due to extensive muscle engagement.
• Assessing the physiological demands of COMP is crucial for optimizing athlete performance and training strategies.

Purpose of the Study:

• To quantify the physiological demands of off-road cycling using portable spirometry, leg-power output (PO), heart rate (HR), and blood lactate (BLa).
• To compare laboratory test (LabT) data with simulated competition (COMP) data to identify key performance determinants.

Main Methods:

• Twenty-four male cyclists underwent simulated COMP and LabT, including maximal workload and ventilatory thresholds (VT1, VT2).
• Measurements included oxygen uptake (VO2), PO, HR, and BLa during both COMP and LabT.
• A high-performance athlete (HPA) was included for comparative analysis.

Main Results:

• Mean oxygen uptake during COMP (VO2COMP) was 57.0 ± 6.8 ml·kg(-1)·min(-1), significantly lower than the HPA's 71.1 ml·kg(-1)·min(-1).
• LabT variables, particularly VO2peak, strongly correlated with racing time (RTCOMP) and POCOMP (r = -0.59 to -0.80).
• VO2peak accounted for 65% of the variance in a single COMP test, indicating its importance.

Conclusions:

• High aerobic capacity (VO2peak) is essential for successful cross-country cycling performance.
• Respiratory gas analysis and power output measurements are more sensitive than HR or BLa for assessing COMP energy requirements.
• LabT data can inform training program design for mountain bike athletes, complementing COMP-derived insights.