Sunday, September 17, 2017

The Plank Variation That Saved All the Puppies

If there’s one exercise that sets the foundation for all others, it’s the front plank.

Think about it.

What’s a push-up? A moving plank. What’s a pull-up? A moving plank. What are we doing with our torsos during squats and deadlifts? Maintaining the flat back posture characteristic of, you guessed it, a plank!

Yet if there’s one exercise that’s notoriously butchered, it’s also the plank.

People often attempt to hold it for way too long (e.g. several minutes on end). And when they do, it’s usually ugly. They lose proper position (a straight line from head to heel) and, therefore, the desired training effect. They also kill all of the puppies in the process.

Over the last few years, likely in response to the puppy-killing plank epidemic, the RKC plank has emerged as a potential solution.

The RKC plank, also referred to as a hardstyle plank, is exactly that: hard. The goal of the RKC plank is to dial up the intensity of the muscular contraction to the max. It should be so intense that any more than a 20-second hold would be utterly impossible. Usually 10-15 seconds suffice.

Whereas in a traditional plank, we’re mostly focused on engaging our abs, in the RKC plank we’re squeezing EVERYTHING:
  1. Abs, by bracing as if to absorb a punch
  2. Glutes, by posterior pelvic tilting
  3. Quads, by locking the knees out
  4. Lats, by pulling the elbows in and down towards the feet, as if to crunch
  5. Fists, for irradiation
  6. Even the anterior tibialis (the muscle on the front of the shins) should be on full blast, pulling the toes up towards the head.

To increase the degree of difficulty even further, the elbows can be positioned slightly closer together and a few inches farther out in front than normal. When this position is used, you might hear it referred to as a “long-lever posterior-tilt plank.”

In addition to saving puppies, the RKC plank is said to transfer well to those other movements that require a rigid trunk position. In other words, generating all-out, global tension in a plank is a low stakes opportunity to practice "getting tight" for heavy squats and deadlifts.

With so many perks to the RKC plank, should we just abandon the traditional plank altogether? Some trainers might say yes, but that would be shortsighted.

Don’t get me wrong – the RKC plank would be the greatest thing since sliced bread, were it not for just one problem. When we perform the RKC plank, we’re applying a high-threshold strategy where a low-threshold one would suffice.

What the hell are high- and low- threshold strategies?!

I’m glad you ask. This conversation was getting awfully one-sided. Basically, it’s science-speak for the idea that we’re trying way harder than we have to in order to execute the task.

The body usually knows best. It reflexively (i.e. automatically) chooses the right amount of tension for the job at hand -- unless we screw with the natural process by consciously revving tension all the way up, as in the RKC plank.

Abdominal bracing like this increases compressive force on the lumbar spine [1]. This compression may not be desirable for individuals with low back pain [2], who already tend to tense their core muscles more than their pain-free counterparts [3].1 High-threshold bracing is also suboptimal for performing basic activities of daily living, which require far less activation of the core muscles [4].

So should we really be reinforcing such a strategy by training people in this way?

Let’s not throw the baby out with the bath water. To reiterate, the RKC plank is an effective way to
  1. Counter people’s tendency to hang out in ugly traditional planks for minutes at a time.
  2. Develop the full-body tension that’s needed to execute heavy compound lifts safely.

But clearly, RKC planks are not for everyone. Nor should all planks be of the RKC variety. There’s still a time and place for well-executed traditional planks.

That time usually lasts for a few sets of 30-60 seconds and serves to train the core reflexively and in more of an endurance role.

I typically begin programing RKC planks after my clients have mastered traditional planks, as I consider them a more advanced exercise. I do know other trainers who start clients immediately with the RKC version with good success, though.

Either way, for individuals who tolerate them well, including both RKC planks and traditional planks in a training program provides the best of both worlds -- not to mention saving the puppies.


1. For decades, it was believed that low back pain was caused by weakness and faulty muscle firing patterns of the core. Based on this premise, many efforts have been made in rehabilitation to improve core stability in individuals with low back pain. In the end, though, it turned out that core stability training is no better than general exercise for individuals with low back pain [5]. This is likely due to pain being more complex than a biomechanical difference in muscle timing or strength alone. There are many other contributing factors to pain, including both psychological and sociological ones.

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