I said in a journal not too long ago that I wanted to start adding more muscular physiques to my art. Well, here's a bit of practice, with red lines outlining the basic points where muscles would be. The blue is for the shapes to make up the rest of the form inside the black lines

Really, muscles in art are nothing more than big circles, ovals, and rectangles. The trick comes from how you stretch other shapes and curves around them. for those who struggle with this sort of thing too, try thinking of everything as a mass of shapes that you have to round out~