Long bending is taking a long piece of steel and putting a single bend in it. While the steel can be the same, this is different from scrolling where you bend the steel into a shape or roll it up.
Very difficult and large pieces of metal can be used in this feat. Putting a bow and then finishing it into a ‘U’ shape. There are several methods on starting the bend. Over the head, across the knee, across the neck and others. Each one requires different skill and strength to pull in a certain angle.
In the video people you can watch a challenge between David Horne and Stewart Killick taking a 40″ x 20.45mm steel bar and bending it to within 11″ within 5 minutes.
This feat of strength is covered in Dennis Rogers and Erik Vinings Basic Scrolling DVD.