Milo of Croton is an Ancient Greek Wrestler who's famous for having carried a calf every day as it grew into a bull. As the calf grew, he slowly gained strength. This story is used to illustrate the concept of progressive overload. (More on Milo of Croton here.)

My specialty is helping skinny guys bulk up, so I use this illustration to show how even a light weight can challenge our muscles at first (the calf), but then as we grow stronger, we need to continue to challenge our muscles with heavier and heavier weights (the bull). If we fail to do that, our muscle growth will plateau, and our bulk will fail.

In fact, it's such an important concept that we've made Milo of Croton the avatar for our Outlift website.

Anyway, here's the illustration:

And here's a mock-up of a book cover for a new bulking workout program we're making:

If you want to see more lifting illustrations, check out Bony to Beastly, Bony to Bombshell, and Outlift.