Mesh shrinks when trying to bend after rigging? I am a beginner at Blender and was following a tutorial that showed how to create a character with a rig and animate it. However, I have come across a problem I can't seem to fix. When I bend the arm for a running pose, the mesh at the elbow looses its volume. I have posted a screenshot below to show the problem.

Blend File: https://www.dropbox.com/s/kui3d18refgecde/charbendingsolutiontry.blend?dl=0
You have to play with weight paint to find the right weight.

When your intention is a like organic mesh, you have to make it as square as possible. this will make the deformations look smoother.

See the image below.