If you're looking for a smart alternative to larger ineffective moves like Dumbbell Side Bends that require even less equipment, Side Planks are your answer.
In addition to the obliques, Side Planks target the quadratus lumborum (QL).
The QL is a deep core muscle that connects the pelvis, spine and rib cage. It works to stabilize the spine and prevent side bend during actions like unilateral pressing.
"If the QL isn't functioning as it should, even basic actions such as walking and breathing will be limited," says Tim DiFrancesco, owner of TD Athletes Edge and former strength and conditioning coach for the Los Angeles Lakers. "The QL functions to provide stability to the pelvis and lumbar spine intermittently as you perform any and all activities."
NFL stars Cliff Avril and Antonio Brown include Side Planks in their ab workouts.
Like with normal Planks, holding sloppy form for marathon-length periods isn't going to do much. You want an intense contraction here, one that should be so taxing there's no way you could possibly hold it for minutes on end. Shoot for 4-6 sets of 8-12 reps, with each rep being an interval of 3-5 seconds.
Proper form is essential here. Some tips from DiFrancesco to make the most of the move:
Avoid Should Sag. This puts unnecessary stress throughout the shoulder and diminishes the effectiveness of the exercise. To avoid this mistake, press your upper body away from the ground during the hold. Fight to keep as much distance between your rib cage and the ground as you hold your Side Plank
Combat Low-Back Arch. Another common mistake is failing to keep the core engaged during the hold. This results in a Side Plank that looks OK from the front, but tragic from above. When you see a Side Plank from a bird's-eye view, you should see a straight line from the ear to the shoulder and all the way to the hip. When you fail to engage the core as if you're about to take a punch, you end up with an arched or curved low back instead of a straight line
Don't Give in to Hip Drop. The hip drop can come from fatigue, lack of awareness, or both. The Side Plank is an anti-side bend exercise. When you let your hips drop toward the ground, you fall into side bend. This means both your QL and glutes are relaxing and no longer being targeted. Keep your hips up and in line with the rest of your body as you hold your Side Planks.