How to Do a Side Plank: Proper Form, Variations, and Common Mistakes

forearm side plank

Verywell / Ben Goldstein

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Targets: Arms, back, core

Level: Intermediate

The side plank is an excellent exercise for strengthening the oblique abdominal muscles, which don't get worked as much during ab exercises such as crunches. You will hold your body on your side in a straight position supported only by one arm and the side of one foot.

Strong obliques can be pretty useful as core stabilization muscles. Beginners must build the strength and balance needed with warmups for the obliques and modified side planks before progressing to the side plank. You can include side planks in your core exercise routine, Pilates, or yoga practice.

How To Do a Side Plank


Strengthen Your Hips with Side Planks

Lie on your right side, legs extended and stacked from hip to feet. The elbow of your right arm is directly under your shoulder. Ensure your head is directly in line with your spine. Your left arm can be aligned along the left side of your body.

  1. Engage your abdominal muscles, drawing your navel toward your spine.
  2. Lift your hips and knees from the mat while exhaling. Your torso is straight in line with no sagging or bending. Hold the position.
  3. After several breaths, inhale and return to the starting position. The goal should be to hold for 60 seconds. Change sides and repeat.

Benefits of The Side Plank

The primary muscles used are the obliques, along with the gluteus medius and gluteus maximus to stabilize the hips. Your shoulder stabilizers keep you aligned as well.

This exercise doesn't put pressure on your lower back or neck as many core exercises do. In pregnancy, the side plank is preferred as it places less stress on the center abdominal muscles. It is a balancing exercise and you will be building your balance and coordination. This exercise can help you be able to sustain good posture and ease of movement by building a strong core and better balance.

Other Variations of The Side Plank

Side Twist

Easing into your side plank gradually before fully loading it with your body weight will likely help you avoid joint and/or muscle strain. This is done with warm-ups and modifications.

Start with warmups before you do the side plank.

Warm up your oblique abdominals with little curl-ups that go to the side.

  1. To begin, lie down on the floor with your knees bent and your feet flat. Perform a few straight-on curl-ups just to get going.
  2. When you're ready, do the little curls over to one side, moving up and down slowly to get the most strengthening benefits.
  3. Do at least five on each side.

Before you add challenge to your obliques, spend a few moments on your back with your knees bent and your feet flat. Gently drop or roll both knees to one side and then the other several times.

If you'd like to turn this move into an oblique challenge, when you pull your legs back to the start position (feet flat on ​the floor) do so from your hip bone only and let your legs dangle like dead weight. The key to making this work is to not allow your legs to help you and keep the abs engaged.

Side Plank From Knees

Woman practising mermaid Pilates mat exercise
Angela Coppola / Getty Images

Now graduate the warm-up into a slight challenge by sitting on one hip with your legs folded behind you.

  1. Help support your body weight by extending the arm that's on the same side as the hip on which you're sitting, and placing that hand on the floor.
  2. Keeping your hip on the floor, lean into your hand. This will give your oblique muscles a bit of isometric work.
  3. Stay there for about 20 to 30 seconds, then repeat on the other side.

Single-Knee Side Plank

Young woman exercising in gym
Austrophoto Austrophoto / Getty Images

If you aren't able to hold the side plank position, the remedial side plank position is a perfectly fine place to develop your oblique strength.

  1. From a sitting position, lower yourself down a bit so that your weight is supported on your hip and the side of the thigh that is closest to the floor. This leg should be slightly bent in order to help facilitate safe and accurate positioning. Your weight should also be supported on the forearm on the same side. 
  2. Try to keep good form and alignment by keeping your upper hip and shoulder directly above the lower. Use your abs. Your top arm can rest by your side or you can put your hand on your hip.
  3. Spend up to 1 minute in this position and then switch sides. Work on keeping good form while you're in the position and try to add 1-2 seconds each time you practice.

Stability Ball Side Plank

Man exercising on a fitness ball in a gym
Glow Wellness / Getty Images

If you remain remedial, you can develop muscle balance and involve the muscles in your ribs more by placing a fit ball or BOSU ball under your flank.

The ball will challenge your alignment and overall body balance. You must maintain your top hip and shoulder directly over the bottom. If you have problems doing this, widen your base of support by putting the top foot in front of the other on the floor.

Increase Intensity

In yoga, the Side Plank Pose (Vasisthasana) is taught with the supporting arm straight. It is also taught this way as a Pilates exercise. This places more stress on the wrist while working additional muscles in the forearm. You can enter the straight arm variation from Plank Pose (Phalakasana). You can also raise both your top arm and top leg for an even greater challenge

Common Mistakes

To get the most from this exercise, avoid these errors.

Hips Sagging

If you haven't built enough strength, you will find your hips sagging and you won't be able to maintain a straight line. When this happens, it means your core is no longer holding you in place and you are not getting the benefit of the exercise. You could also put undo strain on your hips and back.

Rolling Forward

Without enough strength and balance, you may not be able to maintain the position and you'll find yourself rolling forward and unable to keep your hips and legs stacked. If this happens, try to correct it but if it's too difficult, try lowering your bottom knee and maintaining a straight line.

Holding Too Long

At first, you may only be able to hold the side plank for a couple of seconds. As soon as you start sagging or rolling forward or backward, it is time to end the plank before you get a strain injury. Monitor your form and end as soon as you begin to fatigue.

For the queen of all challenges, also lift your top leg. You can do this from the forearm support position or the straight arm support position. You will work your inner thigh muscles in raising the top leg, but there is no need to raise it higher than parallel to the ground. Another variation is to lift the lower leg off the floor, maintaining contact with the foot of the upper leg and your elbow or hand only.

Safety and Precautions

You should avoid side plank if you have an injury to your shoulder, arm, elbow, or ankle. Talk to your doctor or physical therapist about whether it is appropriate if you have any other injuries or conditions. Stop if you feel pain at any time.

Frequently Asked Questions

  • Is side plank harder than plank?

    Side planks are more challenging than planks for most people. This is because you are balancing your body on only one arm and foot rather than on two. A more narrow base requires more core activation to remain stable.

  • Do side planks give you abs?

    Side planks don't give you visible abs. You will need to have low enough body fat levels to see your abdominals. However, side planks do add stability and strength to your core, which is arguably more important.

  • Which type of plank is most effective?

    All varieties of planks are effective, although it's important to choose the one that continues to challenge you. This may mean you start with a particular modified version of a plank, such as against the wall, and eventually perform a plank with arms on a stability ball, for example.

Try It Out

Incorporate this move and similar ones into one of these popular workouts:

2 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Krause DA, Dueffert LG, Postma JL, Vogler ET, Walsh AJ, Hollman JH. Influence of Body Position on Shoulder and Trunk Muscle Activation During Resisted Isometric Shoulder External RotationSports Health. 2018;10(4):355-360. doi:10.1177/1941738118769845

  2. Huxel Bliven KC, Anderson BE. Core stability training for injury preventionSports Health. 2013;5(6):514-522. doi:10.1177/1941738113481200

By Anne Asher, CPT
Anne Asher, ACE-certified personal trainer, health coach, and orthopedic exercise specialist, is a back and neck pain expert.