Bloodflow
You can study anatomy on those guys.
I have quite a circle of bodybuilders around me since i am working out a bit myself. After all the effort and time these guys put into preparation of their physique for competition it would be a sin not to make a small photoshoot in a peak of their condition.
Click to enlarge.
Shot with Nikon D3s 50mm 1.4G f/8 1/250 iso 100
Have fun,
David