Modeling the Power-Duration Relationship in Professional Cyclists During the Giro d'Italia

Vinetti, G, Pollastri, L, Lanfranconi, F, Bruseghini, P, Taboni, A, and Ferretti, G. Modeling the power-duration relationship in professional cyclists during the Giro d'Italia. J Strength Cond Res 37(4): 866-871, 2023-Multistage road bicycle races allow the assessment of maximal mean power output (MMP) over a wide spectrum of durations. By modeling the resulting power-duration relationship, the critical power (CP) and the curvature constant (W ') can be calculated and, in the 3-parameter (3-p) model, also the maximal instantaneous power (P-0). Our aim is to test the 3-p model for the first time in this context and to compare it with the 2-parameter (2-p) model. A team of 9 male professional cyclists participated in the 2014 Giro d'Italia with a crank-based power meter. The maximal mean power output between 10 seconds and 10 minutes were fitted with 3-p, whereas those between 1 and 10 minutes with the 2- model. The level of significance was set at p < 0.05. 3-p yielded CP 357 +/- 29 W, W ' 13.3 +/- 4.2 kJ, and P-0 1,330 +/- 251 W with a SEE of 10 +/- 5 W, 3.0 +/- 1.7 kJ, and 507 +/- 528 W, respectively. 2-p yielded a CP and W ' slightly higher (+4 +/- 2 W) and lower (-2.3 +/- 1.1 kJ), respectively (p < 0.001 for both). Model predictions were within +/- 10 W of the 20-minute MMP of time-trial stages. In conclusion, during a single multistage racing event, the 3-p model accurately described the power-duration relationship over a wider MMP range without physiologically relevant differences in CP with respect to 2-p, potentially offering a noninvasive tool to evaluate competitive cyclists at the peak of training.