Find out how many sit-ups after 55 signal a strong, healthy core and use this 60-second test to track your strength over time ...

Unlike a crunch or sit-up, where you bend through the spine, the dragon flag keeps your body completely straight and rigid as ...

There are two kinds of people in this world: People who want to work their core and people who consider core exercises their worst nightmare. But regardless of which camp you fall into, if you are ...

"Hearst Magazines and Yahoo may earn commission or revenue on some items through the links below." If your body were a bicycle, your abs and back muscles—your core—would be the frame. You need a ...