I've been a fan of Citrusification's muscle artwork for quite some time now, and I colored and shaded one of his sketches just for the fun of it. He has approved the final image, and has given his permission for me to post the result.

The original line art for this image can be viewed by clicking THIS LINK. (Note: This link leads off-site, to FA.)

Line Art © citrusification
Coloring © cashewlou