More, the muscles usually are striped along the lenght, you should include this in the shader (actually disgusting realistic, besides the veins).
Env
Yeah I know about the striations, the problem though is getting them to align with each muscle properly. I think uv mapping is probably the only way to do it properly.
Anyway, I looked through MyIS’ shader to see how he did it and had a bash at my own, though it is very similar.
Just bumming around.
not a very good shader… you need to use UV map and draw the fibers of the muscell and make it go brighter in the top.
I agree with @ner, and the texture also hides all the detail of the modelling. Go with something more simple that doesn’t cover up anything.
Great model!
I think it would look amazing as a superhero suit 
I don’t really like the muscle shaders… they have the good fleshy and muscle type of feeling (definitly the first one), but those voronoi textures don’t really do it good when they are so obvious.
- Bentagon
Indeed, you should UV map each muscle. It will be more beleivable in the end.
BgDM
Aye that was the original plan, it’s just when I saw the muscle shader in the other trhead I had to give it a go and see what it was like 
i thought of the texturing more as each muscel as a different color, or something like a doctors chart
i wonder if you could make money off this, it seems very accurate, wonder if you could make a model/animation/.gif animation/diagram for doctors or schools to use. depending how much time you want to spend working on it and marketing it i think you could find a way to make some money.
anyway its great to see such a dedication to one model, it is very impressive!