The Best and Worst Ab Exercises (And why core strength is essential to your health)

Why is core strength so important? A leading expert in spine biomechanics explains

When it comes to fitness and exercise, the topic of core strength is a popular one, and for good reason; a strong, supportive core is essential to your overall fitness.

Yet, when you’re in pursuit of “the best ab exercises” or “the best moves for a strong core,” it’s not too often that you’ll find a good explanation about why it’s so essential.

According to Dr. Stuart McGill, director of the Spine Biomechanics Laboratory at the University of Waterloo and author of Ultimate Back Fitness and Performance , the importance actually extends beyond athletic fitness and encompasses the entirety of your overall health.

“Every health system depends on movement, and every movement depends on core stability,” said McGill. “Your bones, your digestive system, even your cardiovascular system.”

In fact, he also noted that it’s about more than just core strength.

“Core fitness is not only about strength. What we’ve measured and found is that the endurance of the muscles has much more to do with preventing back pain and overall core health.”

Related: At What Age Can You Safely Start Strength Training?

When I spoke with McGill over the phone, he said there are many, many reasons why, what he refers to as “core fitness,” is vital to your overall health.

“Core fitness prevents back injury, it helps rehabilitate back injury and quite simply, it helps you do things. It’s essential to human movement,” he said.

To elaborate, he provided the example of an engineer building a column.

 “If you’re an engineer and you want to build a column that can bear a load you would use a rigid beam,” he explained. “If you place a load on a flexible beam or flexible rod it collapses. To support it you would need a guy-wire system.”

The human spine is akin to the flexible beam. McGill referred to our muscles (the abdominal wall, internal obliques, external obliques, etc.) as the guy-wire system designed to support the spine.

“When you examine the role of these muscles they function like an orchestra system and create stiffness in the core that allows the column to bear load,” said McGill.  “After that the muscles function to create movement, like when we run, or dance or ride our bikes.”

McGill noted that when talking about core fitness, stiffness is of utmost importance. “You have to stiffen the column so it doesn’t buckle,” he said. “People think muscles produce force, which is true, but they also provide stiffness.”

Here he gave the example of an isometric contraction of the muscles, like clenching your fist for example. He told me to imagine the act of opening a door.

“You wouldn’t be effective if your rib cage moved away from the door, which is why you need core stiffness,” he said. “Once you stiffen the core there’s no motion in the rib cage and muscle force is directed at propelling the arm. An important role of the core is to stop movement.”

McGill also touched upon the topic of back pain, which he says is commonly related with weakness in the core.

“A lot of back pain comes from spine instability,” he said. “If you damage a ligament the joint becomes lax and micro movements will cause pain. If this happens in the spine then you’ll experience back pain.”

So, if core fitness is essential to your health as an exerciser, an athlete and a human in so many paramount ways, then what are the best ways to make sure you maintain strength in those muscles and protect your spine?

McGill says that there’s no one exercise that is exclusively considered “the best,” but that there are series of exercises that you can do every day to increase your core fitness.

“We’ve done a lot of research trying to determine what the best exercise might be, but it’s different for everyone," he said. “In the end we tried to create the best three exercises.”

Those moves include bird dog, side plank and the modified curl up, all of which are demonstrated through video on

And yes, you read that right. McGill recommends doing these exercises every day. He says that the “three day a week” training regimen that you often hear about when it comes to strength training only applies to body builders.

Related: How Much Protein Should You Eat Per Day to Build Muscle?

As far as exercises that you should avoid go, McGill says to steer clear of sit-ups, which he considers one of the worst core exercises of all.

“If you take a wire coat hanger and bend it over and over again, eventually the metal will fatigue and break,” he explained. “The same theory applies to your spine. Who you are determines how quickly that process will wear it down. If you are slim it might take longer, but for a larger person it’s the opposite.”

To sum-up our conversation, I asked McGill what he considered to be one of the biggest misconceptions about abdominal muscles and core exercises.

“There’s an overemphasis on the abdominals. Americans love their six packs,” he said.

He mentioned that many people fail to recognize the importance of engaging all of their core muscles, which McGill says includes the entire torso from the hips to the shoulders.  

“It’s a three-dimensional system,” he said. “You have to hit the full guy wire system.”

For more information on core fitness, spine health and customized programs that include exercise progressions refer to

The 8 Best Yoga Poses for a Stronger, Slimmer Core
8 Epic Ab Exercises for a Firm, Flat Stomach
Strength Training 101: Dynamic vs. Isometric Exercises