Which Celeb Has Frighteningly Fit Arms?

This songbird showed some muscle while stepping out in London...see if you know who it is

This star needs to put down the weights and pick up a sandwich, stat!

The singer showed off her seriously scary arms when she stepped out to dinner in London with her much younger boy-toy.

She's known for having a strict gym routine to keep her famous figure, but by the looks of this pic, she's gone overboard.

Think you know who owns these arms? Find out if you're right...

It's Madonna, departing from a dinner with Jesus Luz.

What do you think of the 50-year-old's figure?