The abdomen is the most problematic area for most people. Luckily, there are many effective yoga poses for this area. Try practicing bellow breaths before you begin. Boat pose is by far one of the most efficient asanas for the abdomen. It can be brutal, but beginners can hold on to their thighs or knees. Of course, the Planks are great and Camel and Cobra will give your abdomen a great stretch.