Side Planks Are a Must-Do Move for Core Strength

Anyone who has done a core workout is likely familiar with planks. Because they are relatively simple and require no equipment, there are many ways to mix up the exercise, including plank jacks and inchworms.

One way to turn a plank on its side—literally—is to do a side plank. By shifting your plank position to one arm, you'll feel your muscles (especially those obliques) work in a new, challenging way. Ahead, fitness trainers Tanya Rockovich and Vicki Chimenti break down everything you need to know about side planks, including their benefits and how to do them the right way.

What Is a Side Plank?

Simply put, side planks, a variation of traditional planks, are stability exercises that strengthen your core, says Chimenti. They tap into your obliques more than a regular plank.

Side planks are also unilateral exercises, as they work only one side of the body at a time, adds Rockovich. They're performed in a side-lying body position where you're using a single arm to lift your body up.

What Are the Benefits of Side Planks?

Side planks strengthen your whole core and body. But importantly, they strengthen your core without putting pressure on your lower back, says Chimenti. Many times, in doing core exercises, we end up putting more pressure on our lower backs than we intend to. Side planks, says Chimenti, are great to help relieve that pressure so you can focus on more stability, which leads to more strength.

While you may think of side planks as a core move, they also work a number of different muscles while supporting your body in a plank position. You’ll feel your external oblique muscles definitely fire up, but side planks also work your transverse and rectus abdominis and serratus anterior, as well as your back muscles, lats, and traps, explains Rockovich. If you add a twist or thread the needle, you also work your internal obliques that are responsible for rotation.  

And because you’re working one side of your body at a time, they can also help you realize any strengths or weaknesses on either side. “Sometimes when we work both sides of our body at the same time, we don't realize we are putting more pressure into one side versus the other," says Chimenti. "When we isolate one side of the body and tap into what that specific side needs, we get to focus more on the little details to make that side stronger.”

How to Perform a Side Plank

Here’s how to make sure you’re doing a side plank with proper form, according to the trainers.

• Starting by lying on your right side, place your forearm on the ground with your elbow positioned underneath your shoulder and your legs straight out.
• Inhale, and then exhale as you press into your forearm and the side of your foot to lift your hips up. Make sure your spine is in a straight line from the top of your head down to your tailbone. Keep your shoulders stacked right on top of your elbow.
• Squeeze into your right side body and your glutes, and engage your external obliques as well as your abs.
• Hold and pose at the top of the movement. Keep breathing.
• Slowly lower down and repeat on the other side.

Pro Tip: Be patient with the process of executing a strong side plank, says Chimenti. It’s easy to let your hips drop or rotate them when you’re in the side position. “We are literally fighting gravity in planks. Take the time to really set yourself up for success, and feel out your positioning and alignment first before jumping right into the plank,” she says.

Focus on your form first, and then work on increasing how long you can hold the position. Rockovich suggests envisioning your body being between two panes of glass, not leaning too far forward or back.

Modifications

Side planks can be modified depending on whether you want to increase or decrease the intensity of the move.

Half-Kneeling Side Plank

If you're just starting out, this half-kneeling side plank will give you a little more support as you lift and hold.

• Starting by lying on your right side, place your forearm on the ground with your elbow positioned underneath your shoulder. Bend your bottom knee and extend your top leg straight.
• Press into your forearm, the side of your bent knee, and the top foot to lift your hips up.
• Squeeze into your right side body.
• Hold and pose at the top of the movement.
• Slowly lower down and repeat on the other side.
  

Staggered Feet Side Plank

Staggering your feet gives you more support in the plank position as you have two points of contact on the ground.

Follow all the same instructions as the standard side plank, but instead of having your feet stacked on top of each other, stagger them with one in front of the other. You'll push into both feet to lift your hips.

Straight Arm Side Plank

Doing a straight arm side plank will work your wrist and additional muscles in your arms and shoulders.

• Starting by lying on your right side, place your hand on the ground underneath your shoulder with your fingers pointing away from you, and extend your legs.
• As you lift your hips, make sure your shoulder stays over your elbow and wrist in a straight line.

Side Plank with a Leg Lift

Add some movement into your side plank for an extra challenge.

Start in the same position as the straight arm plank with your feet stacked. Lift your hips into a plank position. Maintaining a straight line, flex your foot and lift your top leg to just above hip height. Lower your leg back down.

Safety Considerations

Side planks are suitable for most everyone. “Even our pregnant clients benefit greatly from side plank work. Just always make sure you take the modification option and listen to your body,” says Rockovich.

However, if you have any shoulder, elbow, or arm pain, you should avoid doing side planks. Adding pressure to joints or bones that are already irritated will only cause more pain, says Chimenti. And if you have any questions or concerns, always check with a doctor before trying any new exercises.

The Final Takeaway

Side planks are a great core strengthening exercise, and they work so much more than just your abs. They engage one side of your body at a time and use your shoulders, obliques, and hips to stabilize your body in the plank position. As with most exercises, proper form is crucial for optimizing the benefits of the move and preventing injury, so it's important to make sure your body stays in a straight line from head to toe.

If you have any prior shoulder, arm, or joint issues, side planks may not be the right exercise for you. But if you can safely do them and are a beginner, there are modifications you can use until you get stronger, such as putting a knee (or both) down or staggering your feet to provide more stability. And for those ready to progress your core workout to the next challenge, you can move from your forearm to your hand, or incorporate leg lifts into the side plank.