Range of values of the local viscosity predicted by the rotationally induced processes discussed in Sect. 3 across the MS, for 1.3 M_⊙ (in black) and 2 M_⊙ (in grey). For both models, (Ω/Ω_c)_i = 0.1. The red band indicates the range required for a uniform viscosity to match the observations (Sect. 3.1). The maximum extent of the convective core throughout the evolution is indicated by the dotted lines for both masses.