  We calculate a grid of models with and without the effects of axial rotation
for massive stars in the range of 9 to 60 M$_{\odot}$ and metallicity $Z$ =
0.004 appropriate for the SMC. Remarkably, the ratios
$\Omega/\Omega_{\mathrm{crit}}$ of the angular velocity to the break-up angular
velocity grow strongly during the evolution of high mass stars, contrary to the
situation at $Z$ = 0.020. The reason is that at low $Z$, mass loss is smaller
and the removal of angular momentum during evolution much weaker, also there is
an efficient outward transport of angular momentum by meridional circulation.
Thus, a much larger fraction of the stars at lower $Z$ reach break-up
velocities and rotation may thus be a dominant effect at low $Z$. The models
with rotation well account for the long standing problem of the large numbers
of red supergiants observed in low $Z$ galaxies, while current models with mass
loss were predicting no red supergiants. We discuss in detail the physical
effects of rotation which favour a redwards evolution in the HR diagram. The
models also predict large N enrichments during the evolution of high mass
stars. The predicted relative N-enrichments are larger at $Z$ lower than solar
and this is in very good agreement with the observations for A-type supergiants
in the SMC.
