GET TO THE HEART OF CORE TRAINING
Claims that certain muscles should be targeted lack credibility, scientists say
Back in the day, the only attention given to your midsection was adding a few sit-ups to your workout routine. That changed with the idea that a strong core is not only the key to a healthy back, but is also the power behind athletic performance. And so started an almost endless stream of workouts promising to build core strength.
But despite the hype around core training, there’s a paucity of research backing claims that it offers more benefits than a wellrounded strength-training regimen that includes, but doesn’t single out, the core muscles. And while the importance of the core’s ability to transfer energy between the upper and lower body and sustain postural control during activity is not in question, the type of conditioning needed to optimize the core’s ability to improve performance and reduce the risk of injury remains untested.
It doesn’t help that the terminology around core training is confusing, including the question of what constitutes core muscles. We once used the term “abs” to define the group of muscles around our belly. Today’s definition of the core generally encompasses all the muscles located between the shoulders and hips. Then there are the many terms describing core workouts, often with no clear definition. Core strength, core stability, functional strength and core mobility are all commonly used when referring to core training.
If that’s not confusing enough, there’s the idea that the core can be segmented into regions, with trainers offering exercises that target the “lower abs” or the “deep muscles” of the core.
In an effort to provide scientific clarity for many of the claims related to core conditioning, a team of German scientists evaluated much of the existing research. They tackled topics such as the importance of rotational exercises, training on unstable surfaces and so-called “functional” exercises.
Based on their findings, science doesn’t support the idea that the trunk muscles work independently; rather, they should be considered a single unit, with muscles that work synergistically to facilitate movement. Therefore, any claim that certain muscles should be preferentially targeted, or are more important in maintaining core stability or movement, lack credibility. The scientists also failed to find any proof that athletes suffer from specific weaknesses that would necessitate a program targeting the so-called deeper “core stabilizers.”
Next on their list is the appeal of rotational exercises, which are often used to improve the trunk’s range of motion. The scientists contended that improving core mobility is actually contrary to the goal of core stability training, which is designed to limit rotational movements.
“The integration of rotational movements in strength and conditioning training is not at all ‘functional’ and only increases the possibility of overuse damage and injury,” said the authors.
They cautioned that any rotational exercises be initiated from the hips and maintain a fixed trunk. The authors also noted a dearth of information supporting the practice of training on unstable surfaces, such as exercise balls. They argued that the ability to train with more weight while exercising on a stable surface is more effective at building core stability than training with less weight on an unstable surface. They also stated there’s no proof that exercising on an unstable surface engages more of the deeper core muscles than the same exercise performed on a stable surface.
“In light of the lack of evidence for strength training efficacy on unstable surfaces, it is astonishing how frequently it is recommended,” said the authors.
Finally, they suggested that the best functional core exercises are those that resemble sport-specific movements or those we practise during everyday life, which caused them to reflect on the value of exercises like the plank.
“We cannot think of any situation, either in sports or in daily life, where those motor actions take place,” said the authors.
Scott Livingston, a performance coach who has trained Olympic and professional athletes, agrees that core training has lost its purpose.
“People have lost sight of the intent of what they’re trying to achieve with the exercises they are selecting, and instead go to a library of core exercises and pick one,” said Livingston. “We’ve got to understand the desired outcome of the exercise, then choose an exercise that connects with that intent in the appropriate context. This gets lost in favour of throwing spaghetti at a wall and hoping it sticks.”
Bottom line: there seems to be little evidence that classic strength training exercises like squats and dead lifts — which target multiple muscles, including those in the core — are less effective at building core strength and stability than those that target one or two core-specific muscles.
So follow Livingston’s advice and rethink your core conditioning program in favour of one that is specific to your fitness goals.