It may just look like a lot of arm swinging, but any proper twerking session requires serious ab strength. Miley Cyrus, current queen of viral twerking videos, clearly has the physique required. Over the past few years, the 20-year-old singer has very publicly slimmed down and toned up thanks to a rigorous, almost-daily Pilates regimen.

She's happy to show off the results of all that hard work in the look of the moment: a crop top. Miley, though, was wearing crops way before they were mainstream. She selected a dressy one for the Hunger Games premiere last year, scandalizing red carpet commentators and almost upstaging fiance Liam Hemsworth; picked another for a sexy spread in Cosmo magazine; and donned a spiked black leather dominatrix style for her VH1 Divas "Rebel Yell" performance, which allowed her ample range of movement for all sorts of crotch and boob grabbing.

We don't blame her, though—because as far as abs go, Miley's are pretty much perfect. She says as much herself in her Twitter bio, writing, "im a dime. best top of the line. cute face slim waist with a BIG behind." (See Miley showing off that behind in nine different pairs of short-shorts here!) Judge for yourself with seven shots of her stomach, below, in various states of semi-undress.

Just a casual, everyday outfit. Image via.

At Marc Jacobs' New York Fashion Week show. Image via Andrew Rocke/Splash News.

Leaving Pilates class. Image via Splash News.

Busting out on the red carpet at the Hunger Games premiere in LA. Image via Suntzulynn for LE/Splash News.

A normal cold weather Miley outfit. Image via Jacson/Splash News.

On vacation, getting some sun. Image via.

The most intense crop top ever created, worn to perform at VH1 Divas in December. Photo via Tumblr.