The rotational velocities presently obtained via spectroscopic observations of a group of moderately rapidly rotating, chomospherically active single giants indicate that Gray's (1989) rotostat hypothesis requires modification. Their rapid rotation appears to be due to high Li abundances, and results in increased chromospheric activity. A scenario is projected in which the surface convection zone reaches the rapidly rotating core just as a star begins its first ascent of the giant branch, and dredges both high angular momentum material and freshly synthesized Li to the surface.
Fekel, F.C.; Balachandran, S. "Lithium and Rapid Rotation in Chromospherically Active Single Giants" Astrophysical Journal v.403, p.708 (1993)