Ab Roller
Main muscle: Abs
Other muscles: Shoulders
Mechanics type: compound
Fitness level: intermediate
Category: Increase strength

  1. Hold the Ab Roller with both hands and kneel on the floor.
  2. Now place the ab roller on the floor in front of you so that you are on all your hands and knees (as in a kneeling push up position). This will be your starting position.
  3. Slowly roll the ab roller straight forward, stretching your body into a straight position. Tip: Go down as far as you can without touching the floor with your body. Breathe in during this portion of the movement.
  4. After a pause at the stretched position, start pulling yourself back to the starting position as you breathe out. Tip: Go slowly and keep your abs tight at all times.

Caution: This exercise is not advised for people with lower back problems or hernias.

Variations: If you are advanced you can perform the exercise moving the ab roller to the sides in a diagonal fashion as opposed to straight forward. This version places more emphasis on the obliques.
Source: bodybuilding.com