Validity of using functional threshold power and intermittent power to predict cross- country mountain bike race outcome

Validity of using functional threshold power and intermittent power to predict cross-country mountain bike race outcome. Purpose: Field tests are important for athletes and sport practitioners as they offer valuable information on performance without demanding the time and cost to visit a laboratory. This study tested the ability of relative functional threshold power (FTP) and intermittent power (IP) field tests to be used as predictors of cross-country mountain bike (XCO-MTB) race finishing time. Methods: Eleven well-trained male XCO-MTB cyclists (mean age: 35.8 ± 8.2 yr; mean mass: 80.8 ± 13.4 kg) volunteered for this study. Relative (W/kg) FTP and relative IP were collected from field tests with the mean of all intermittent work intervals recorded as IP and FTP calculated from 95% of mean maximal 20-minute power. Race performance time was collected during a mass-start 17.4 km simulated XCO-MTB race in the field. Results: Both IP (r 2 =0.786) and FTP (r 2 =0.736) models were able to significantly predict race performance (p < 0.001). However, the prediction errors were less when using Relative IP than Relative FTP (273.5 s versus 303.6 s). Conclusion: A field-based IP test can be used as a benchmark for the determination of XCO-MTB athlete ability and preparedness. Considering IP can be measured on a stationary trainer in any location and independent of expensive equipment, coaches can easily use this model to track athlete training.