Hey there! When it comes to the abs, you can think of them in a much more simplified way. Doing this will help you add better volume later on and also make it easier to draw the muscle group from different angles. The whole abdominal group can be simplified into a bullet-like shape. From there, you can draw that form in different perspectives and divide the inside into 4, 6, or 8 smaller sections. On the other hand, the way you drew the chest muscles is a bit inaccurate. When the arm is raised, the muscle doesn’t keep the same shape; it stretches. It’s also important to keep in mind how the pectoral muscles connect to the arm bone, since that connection is what influences the movement. Another thing worth mentioning is the angle you’re drawing from. I think you intended to create a 3/4 view, but the drawing itself reads more like a side view, which makes the form feel flatter. I’d recommend studying Michael Hampton. His way of simplifying muscles is very clear and easy to understand. Hope this helps!
