The Dumbass Chronicles: Plank

If you've never done a plank, I will eat the bike shorts I wore for tonight's spin class.

This is the kind of bad ass exercise that we all want to be able to hold for at least 5 minutes. I know some coaches who swear you don't have core strength unless you can hold plank for a minute solid. I've had people in the gym say to me, "Wow! You've been doing that through three of my sets!" Holding plank for what seems like an eternity gives us a great burn. We feel it throughout the gut ("high" abs, "low" abs, "deep" abs, etc.), and it completely exhausts us. Must be a pretty good exercise, right?


Here's the thing, though: it doesn't work.


You know the idea of specificity, right? Basically, it means that if you want to get better at doing what you do (i.e. swimming, biking, running), you have to do what you do. In the case of weight lifting, it means strengthening movements and muscle engagements that you would use when you're swimming, biking, and running (hence "sport-specific" training). The reason it makes sense to most of us to hold the plank for ten minutes at a time is that that's what you're doing when you're swimming, biking, and running--holding your abs tight for sometimes hours at a time. Right?


Not really. Try this: Put one hand on your upper back just below your shoulder blade (lats) and one hand on your lower back just above your hips (QL). Now try walking around holding perfect posture and actively engaging your core. Feel those muscles flexing with each step? When you take a step, your muscles engage on the opposite side to stabilize your body. Now put a hand on either side of your spine about halfway between your shoulder blades and hips and walk around. Feel that? You should feel each side of the muscles along your spine contracting as you take steps.


Those muscles--the QL, the lats, the multifidus--are all parts of your core. But they weren't engaged the whole time, right?


What I'm getting at is that you don't hold the muscles of your core tight the whole time you're running, biking, or even swimming. Those muscles are constantly flexing and releasing to stabilize your body; they are anchoring against whatever's available--bike seat and pedals, ground, even the rest of your body--to provide you with stability and power. The key point is that they're constantly engaging and releasing. Not engaging and holding. Hence the limited specificity of holding plank for a full song on your iPod.


Does that mean that plank isn't useful? Not at all! Plank does get really good engagement through your core musculature, from the superficial abdominals and back muscles to the deep abdominals, spinal stabilizers, and legs. However, the key to using plank in your training is the initial firing of those muscles simultaneously. In short, you want to make those muscles better at working together, firing in concert with each other. So the most important part of plank isn't the last 30 seconds; it's the first 2.


My suggestion is that you hold plank for no more than 20 seconds at a time. The way I'm currently doing plank (when I do plank) is in a Tabata format: 20 seconds on, 10 off. Repeat that 8-10 times, and you should be sufficiently fried.


By the way, as long as I'm on the topic, I'll post a guide to proper form and a few alternatives to plank. I'll try to get that up within the next two weeks.


Sources:
AKUTHOTA, V., A. FERREIRO, T. MOORE, and M. FREDERICSON. Core stability exercise principles. Current Sports Medicine Reports,Vol. 7, No. 1, p. 39-44, 2008.
Fredericson, Michael and Tammara Moore. Core stabilisation training for middle- and long-distance runners. New Studies in Athletics, Vol. 20, No. 1, p. 25-37, 2005.
McGill, Stuart. Ultimate Back Fitness and Performance. Wabuno Publishers, 2004.