Body size as a determinant of the 1-h cycling record at sea level and altitude

This study was designed to validate models for predicting the two Union Cycliste Internationale (UCI) classifications for the 1-h cycling record at sea level and altitude. Specific attention was paid to the integration of model components that were sensitive to scaling differences in body mass (m_b). The Modern Aero Position model predicted UCI Best Hour performances using predictions of total projected frontal area (A_P) that included use of an aerodynamic bicycle and aerodynamic handlebars. The Traditional Racing Position model predicted UCI Hour Record performances using predictions of total A_P that include use of a “Merckx-era” bicycle with drop-style handlebars. Prediction equations for A_P, as well as the coefficient of drag and metabolic power output , involved scaling relationships with m_b, while other model components were similar to previously published 1-h models. Both models were solved for the distance cycled in 1 h (D_HR) using an iterative strategy. Chris Boardman’s current records for the UCI Best Hour Performance (56.375 km) and the UCI Hour Record (49.202 km) were underpredicted by only 0.332 km (-0.6%) and 0.239 km (-0.5%). Both models, regardless of altitude, suggested that D_HR should scale with m_b to the +0.174 power (D_HR∝m_b^+0.174), which is lower than the +0.32 exponent recently suggested in the literature. Lastly, the same models also predicted that six-time Tour de France winner, Lance Armstrong, could exceed both of Boardman’s current records at sea level by about 2.0 km.