4 Plank Variations for Six-Pack Abs.

Star Side Plank

Lie on right side, hips and legs stacked. Place right hand on floor below shoulder and lift hips. Bend left knee. Hold position (as shown) or straighten leg, grasping toes. Hold 30–60 seconds; switch sides.

 Mountain Climber Pushup

Begin in full plank. Draw right knee to right elbow while lowering into pushup. Press up and lower right leg to plank. Repeat on left side; continue for one minute.

Side Plank

Lie on left side, hips stacked. Place left hand on floor under left shoulder. Lift hips, forming straight line from head to heels. Extend right arm above shoulder. Hold 30-60 seconds, switch sides.

 Balancing Plank

Being in full plank position. Lift right arm forward to shoulder height; at the same time, lift leg to hip height, keeping hips square to floor. Hold 30 seconds; switch sides and repeat.