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By Amber Sayer published 28 July 22

A physical therapist explains the benefits of the plank exercise as well as challenging plank variations to try

There’s a good chance you’ve heard of the plank exercise if you have spent time working out at the gym, or perused fitness magazines or online articles. You may even have gotten down on one of the best yoga mats (opens in new tab) and tried this popular core exercise at one point or another.

For regular gym goers, athletes, and fitness enthusiasts, the basic plank exercise – or more advanced plank variations – are among the mainstays of most workout routines. 

This core exercise is ubiquitous for a reason: it works. There are also many ways to modify a plank, depending on your strength and goals, which means that it’s a bodyweight exercise that can “grow” with your fitness level.

To learn more about how to properly perform a plank and the best plank variations to try, we spoke with Kristina Kehoe, a physical therapist, Registered Yoga Teacher, and the Owner of Simpli Whole, a physical therapy practice. 

Kristina Kehoe gained her doctorate in physical therapy in 2015 from the Ohio State University. She is the owner of Simple Whole (opens in new tab) , a physical therapy practice located in Ohio. 

Most people have heard of the plank exercise, but there are also plenty of misconceptions about what this move entails. 

Although there are lots of variations and modifications, a plank is an isometric exercise that targets the core – so if you’ve ever wanted to know how to get a stronger core (opens in new tab) , you’ll find the plank figures highly.

“A plank typically involves assuming a push-up type position and maintaining that position for a specific amount of time,” explains Kehoe. “There are a variety of variations of the plank that can target different areas of the core.”

The basic forearm plank is performed with your body propped up from your elbows with your forearms and toes on the ground. 

The different plank variations may recruit additional muscles or add forms of resistance, instability, or movement to progress or regress a basic plank.

Kehoe says that the primary muscles activated during the plank exercise are those that make up the core (opens in new tab) , such as the transverse abdominis, the rectus abdominis, and the internal and external obliques. 

“The transverse abdominis is our deepest core muscle. This muscle acts as a corset and attaches to our pelvis then wrapping around our front to the lumbar spine. It helps stabilize the spine in all movements,” explains Kehoe. “The rectus abdominis is the ‘6-pack’ abs that run on the front part of our abdomen. The obliques run on the sides of our abdomen and help in overall stability.”

In addition to these abdominal muscles, planks activate other muscles of the core such as the erector spinae in the lower back, the serratus anterior in the upper back, the latissimus doors, and the glutes. Most plank exercise variations also engage the deltoids in the shoulders and pectoralis major and minor in the chest.

Personal trainers, strength and conditioning specialists, and sports coaches around the world use the plank as a go-to exercise for their athletes. But why are planks such a popular core exercise? What makes a plank more effective than crunches or old-school sit-ups? And why are core muscles important? (opens in new tab)

According to Kehoe, one of the primary benefits of the plank as a core exercise lies in its safety.

“The plank is an effective exercise because it doesn’t put a lot of compressive force on the lumbar spine like exercises such as full-sit ups or back extensions. Therefore, it’s a safer option especially if you’ve had a recent back injury,” she notes. 

“Additionally, the plank exercise and variations have been shown to improve core muscle endurance as well as stability and are effective in improving overall core strength in pre- and post-testing with the McGill Torso Muscular Endurance Test.”

Kehoe adds that other benefits of the plank as a core exercise is that it’s a bodyweight exercise that does not require equipment and it can be modified to target different muscles or fitness levels. “There are a number of ways to progress planks to decreasing support on a surface, adding an unstable surface, or adding dynamic movement,” she says.

Before we delve into some more advanced variations, let’s review how to perform the basic plank exercise. A plank can be performed on your hands so that you’re in a push-up position, or on your forearms.

After you’ve mastered the basic forearm plank, you can progress your core strength with more advanced plank variations. Kehoe walked us through a few of her favorite plank variations:

The side plank targets your obliques, the muscles on the side of your abs, and your gluteus medius, a key hip abductor muscle. It’s also slightly more challenging than a standard plank because you are decreasing your base of support from two arms and two feet to one arm and one foot.

Kehoe offers some form tips. Avoid sinking into your shoulder and imagine pressing up through your elbow and forearm for stability. "This will limit unnecessary strain on your shoulder,” she advises. “Don’t allow your hips to dip and maintain an even position so you get the most activation of your core muscles.”

This plank modification further progresses the side plank by adding rotational movement, which Kehoe says is great for improving functional core strength for sports like golf and tennis. Her advice is, “Only reach as far as you can while still maintaining a stable side plank and increase this as you feel stronger.”

Kehoe says you should perform this exercise slowly to really activate your oblique muscles and imagine pressing the mat away with your forearms to avoid sinking into your shoulders.

In addition to adding an aerobic component to the isometric plank, which will elevate your heart rate and calorie burn, the plank with mountain climbers will really target the front of the core (the rectus abdominis muscle).

According to Kehoe, “Plank jacks will help increase the heart rate to add more of a dynamic movement to a typically isometric exercise. It will help burn more calories while targeting the outer and inner thighs as well.”

Amber Sayer is a fitness, nutrition, and wellness writer and editor, and contributes to several fitness, health, and running websites and publications. She holds two masters degrees—one in exercise science and one in prosthetics and orthotics. As a certified personal trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, Amber likes running, cycling, cooking, spending time outside, and tackling any type of puzzle.

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