Exercises for your core you can do with a stability ball.Exercises for your core you can do with a stability ball.

Medicine Ball Russian Twist Standing

Primary Muscle Group: Abdominal Obliques

Muscle Groups Worked in This Exercise:   Obliques and Lower Back

Preparation: Stand straight up with back and head, holding a medicine ball extended straight out from your core front region.  Make sure that your elbows are slightly bent and you keep your head and back straight during the entire exercise movement.

Breathing:  Breath out on the contraction of the muscle and breath back in on the way back to the start position.

Medicine Ball Lying Oblique Twist

Lie face up on floor, knees bent with feet on floor and neck straight. Grasp medicine ball and hold at chest level. In a controlled motion, keeping neck straight, curl upper body up. From this position, twist your torso to the left. Contract abdominals fully without compromising form. While maintaining the controlled motion, return to starting position and continue through to your right side. Focus on really twisting your torso and feeling the contraction when twisiting your torso.

Ball Side Lifts

Lie face down with ball under your hips. Bend your left knee and lift up towards your chest. Finish by extending and driving your left leg behind you. Return to the starting position and repeat.

Bent Arm Medicine Ball Twist

Primary Muscle Group: Abdominal Obliques

Muscle Groups Worked in This Exercise:  Psoas Major, Iliocastalis lumborum, Iliocastalis thoracis

Preparation: Stand holding medicine ball between hands as pictured with elbows bent. 

Legs slightly bent and back and head straight up.

Breathing:  Breath out on the contraction of the muscle and breath back in on the way back to the start position.

Ball Side Lifts

Lie face down with ball under your hips. Bend your left knee and lift up towards your chest. Finish by extending and driving your left leg behind you. Return to the starting position and repeat.

Ball Waistline Trimmer

Primary Muscle Group: Internal and External Obliques

Muscle groups worked in this exercise:

Preparation: Lie on the floor on your back with knees bent and place both heels on the ball. Now, interlace your fingers behind your head and make sure your elbows are out to the sides.

Exercise Ball Pull-In

Exercise Ball Pull-In

Exercise Data
Main Muscle Worked: Abdominals
Other Muscles Worked: None
Equipment: Exercise Ball
Mechanics Type: Compound

Ball Waistline Trimmer

Primary Muscle Group: Internal and External Obliques

Muscle groups worked in this exercise:

Preparation: Lie on the floor on your back with knees bent and place both heels on the ball. Now, interlace your fingers behind your head and make sure your elbows are out to the sides.

Exercise Ball Crunch - Core ball exercises

Exercise Ball Crunch

Exercise Data
Main Muscle Worked: Abdominals
Other Muscles Worked: None
Equipment: Exercise Ball
Mechanics Type: Isolation