The dumbbell side bend exercise works the oblique muscles (which are the muscles on the sides of your abs.)

Steps :

1.) Start off standing with your feet shoulder-width apart with your knees slightly bent and abs drawn in.

2.) Grab a dumbbell lin one hand, stand up straight and then bend at the waist to one side of your body as far as possible.

3.) Hold onto the position for a count, squeezing your abdominal muscles and the return back to the starting position.

4.) Switch to the other side and repeat for as many reps and sets as desired.

Tips :

1.) Be careful to bend only at your waist and not at the hips or knees.