Effect of internal magnetic fields on the redistribution of AM during the MS (evolution goes from left to right). Left: core rotation rate. Right: surface rotational velocity. The surface velocity of the models are multiplied by a factor π/4 to average over the unknown inclination angles of the sample. The models have an initial mass and metallicity of M = 1.5 M_⊙ and Z = 0.01, and are computed at three different initial velocities. The data points in the right panel are contained in the data set of the left panel.