At the supports reaction forces will be generated (because of equilibrium), which will be of similar magnitude as that of applied forces. If you have applied the supports boundary conditions at only few nodes, these large reaction forces will lead to elements distortion.
Abaqus usually scales the deformation to a visible scale - it does that by default. The image you uploaded shows a deformation scale factor of 7.727 (indicated in the state block - the text at the bottom). Go to "Options" menu and click in "Common..". Check that in the "Basic" tab the "Deformation scale factor" is set as "uniform" with a value of 1. It could be just a visualisation problem.