How to Do a Side Plank Correctly: Proper Form for Beginners
Side planks will take your core strength to the next level while also fortifying your low back.
By Kelan Ern Updated: 07/28/26
When I first did a side plank, it was brutal.
It was in junior high PE class, and I could barely hold my body up for even a few seconds before collapsing to the floor. It was much harder than sit-ups... crunches... or other core exercises. And that's one reason people avoid it.
It's exposes a major core weakness.
One that can increase your risk of injury and low back pain.
In this side plank guide, you'll discover how to do this powerful exercise correctly so you can build next level core strength that supports your everyday life.
What are Side Planks?
Side planks are a side-lying core exercise that targets your external obliques and deeper core muscles (such as TVA and QL).
It's foundational for building a midsection that will support you when lifting weights overhead, carrying heavy suitcases or doing tougher core training. Simply hold this side-lying position for 10... 20... or 30 seconds and you'll light up these lateral core muscles in a way sit-ups or crunches can't touch.
(Which we'll get to in a moment)
So why are they important?
Three Benefits of Side Planks
#1: Strengthens the Outer and Inner Core
Think of the core muscles like inner and outer walls of a building.
The "outer wall" are the muscles around the outside of the midsection - the six-pack muscles such as the abs and obliques (which run along the sides of your abdomen). Most fitness enthusiasts only care about these beach muscles.
The "inner wall" muscles like the TVA and QL get far less attention because they are not visible. In fact, most people don't know where they are, let alone that they even exist! (In just a moment, you'll be one of the few). But these deep core muscles work behind-the-scenes to protect the spine and help you move pain-free.
Side planks are special because they work both outer and inner core muscles together. According to Dr. Stuart McGill, one of the top spine experts on the planet:
“It [side plank] is one of the few exercises that works to integrate the QL muscle together with the abdominal wall.”
#2: Lower Back Health
When these core muscles are firing properly (and together) they create super stability at the lower back. This helps protect your spine when you're shoveling your driveway... moving a futon... or lifting a dumbbell off the ground.
More low back stability = more protection from injuries.
In fact, a 2016 study found that lack of core endurance was one of the largest predictors of generalized lower back pain.
Plus, this increase in spinal stability has been shown to even...
#3: Reduce Spinal Curvature
Yes, research has shown that side planks can even help with scoliosis (sideways curvature of the spine).
In a small study published in the journal Global Advances in Health and Medicine, 25 subjects were told to hold a side plank for 90 seconds, 3 days per week for 3 months.
The result: All subjects reduced the spinal curvature by at least 32%. Some reduced it by as much as 49.6%!
Side Plank Muscles Worked
Side plank targets three main core muscles: external obliques, TVA and QL.
Each plays a unique role in stabilizing the spine, maintaining good posture and supporting you during everyday activities. Together, they create a stronger, more balanced core.
External Obliques
If you put your hands in your front pockets, that follows a rough path of your external obliques. These muscles help you rotate your torso, bend to one side and prevent you from collapsing sideways.
Transverse Abdominus (TVA)
Beneath your abs and obliques is the TVA. It's sometimes referred to as the "corset muscle" because it runs horizontally across the midsection. It reflexively stabilizes your spine whenever you move your arms and legs. If a fitness professional has ever told you to pull in your belly button to your spine during a workout, it's to activate this core muscle.
Quadratus Lumborum (QL)
The QL attaches in your lower back from your lowest rib to the top of your pelvis. This deep core muscle helps hold you upright and stabilizes your spine when you bend to the side.
How to Do a Side Plank Correctly
The Set-Up: In the video below, you'll see how to set-up for the modified and regular side plank. Note: You're not just lifting your hips - you're pushing them forward, similar to a glute bridge, to achieve proper alignment.
Modified Side Plank: Lay on your side with your elbow underneath your shoulder. Have your knees bent and your hips back. Bring your hips forward as you lift your torso. Hold this position for 10-60 seconds each side. Regular Side Plank: Lay on your side with your elbow underneath your shoulder. Have your legs straight with your top leg in front of the bottom leg. Start with the hips back. Bring your hip forward as you lift the torso. Hold this position for 10-60 seconds each side.
Two Common Side Plank Mistakes
Mistake #1: Head forward Don’t let your head jut forward. Bring your head back with a slight chin tuck (think make a double-chin)
Mistake #2: Rounding forward Don’t let your body roll sideways. When you raise your arm it should point towards the ceiling.
Side Planks for Beginners
Side planks can be rough. If modified side planks is still too difficult, here's another variation to make them more manageable:
Wall Side Plank: Stand in a staggered stance (one foot in front of the other) and lean against the wall. Keep your body in a straight line. Don’t let the hips sag as you do so. Hold this position for 10-60 seconds each side.
Note: Just like the other variations, keep your head in a proper position (not jutting it forward). Also make sure your spine is in a straight line.
Oh, and make sure the wall is solid. Avoid using bookshelves...dressers... or screen doors ;)
Why Does My Shoulder Hurt During Side Planks?
Shoulder discomfort is the #1 compliant when doing side planks.
This is common since you are loading your weight on one arm - especially if you lack shoulder stability. If you have a history of shoulder pain (or impingement), be cautious with side planks. In some cases, you might want to avoid them altogether and opt for option #2 below.
Here are a few options for alleviating this pressure on the shoulder:
Option 1: Hand on Shoulder Grab the shoulder with an open hand and actively try to pack the shoulder down (opposite of shrugging your shoulders). This stabilizes the shoulder, gives you more clearance at the joint, and can alleviate the pressure.
Option 2: Side Lying Leg Raise: Lay on your side with one hand in front of you and a pillow underneath your head. Keep your body in a straight line and raise your legs. Hold for 10 seconds. Repeat five times each side.
Advanced: Side Plank March
If side planks are a piece of Angel food cake and you want to crank up the intensity a few notches - here's an advanced side plank variation that will do the trick.
Credit for this brutal variation goes to strength coach Eric Cressey. The side plank with march will challenge your obliques way more than a regular side plank. And it's going to fire up hip muscles (like the glute medius) that are crucial for knee health. Do 10-20 marches per side.
(Psychologically this variation is great because you are counting reps instead of staring at the clock.)
Which Side Plank Should You Start With?
Usually I'll start most clients with modified side planks. Why? I'd rather start too easy and build up their core endurance than start too hard.
If those are too difficult, I'll adjust to wall side plank.
If they are too easy (meaning they can hold them for 60 seconds on both sides), then I'll move to regular side planks.
Either way, it's one of the biggest bang-for-your-buck exercises because of how many core muscles it works at once. Remember: it's not just working "outer core" muscles but "inner core" muscles as well.
Plus, it will give you the foundation and fortitude to work your way into more advanced side plank variations.
Whether you do them in your warm-up, during your workout or randomly during commercial breaks - this is an exercise to master and see how much stronger your core becomes.
Kelan Ern Elite Fitness Coaching
P.S. If you need an extra nudge to stay motivated and go further, faster on your fitness journey - grab a free issue of the Mind-Body Breakthroughs where I do a deep-dive on the mindsets and strategies of some of the fittest athletes of all time.
