Tuesday, May 15, 2012

Integrated Core Exercises for Six-Pack Abs: New EMG Data Questions Efficacy of Crunches, Extensions & Co.

Image 1: Jersey Shore or a fortified core,
what do you chose? (img mediabistro)
If you train in one of the mainstream gyms, you will probably already have realized: It is May, and the beach season is approaching! Now, that it is almost too late for the chubby coach-potatoes to get in shape, they finally realize that their never-existent six-pack is buried under several layers of flabby adipose tissue... so what do they do? Right, they perform the most ridiculous contortions, .. ah, pardon, "ab-exercises" you can think about and talk to their pre-obese neighbor on the right about how they feel their abs working during their latest and greatest Men's Health, Shape and Co "Jersey Shore Ready Beach Workout 2012" ;-)

Strong core and six-pack abs, anyone?

Most of the aforementioned spring-break warriors would be better off dieting hard, and lifting heavy, but I don't have to tell you that, right? Lean or about-to-be-lean as you are, you are probably more interested in which ab-exercises will complement your balanced workout routine best, right? According to the latest research from scientists at the Pennsylvania State University and Le Mills International in Auckland City, NZ, these are not the classic crunch, the oblique crunch and the extensions, everyone is doing for the rectus abdominis (what people usually call their "abs"), the obliques and the musculature of the erector spinae (Gotschall. 2012).
Figure 1: Normalized EMG data for the different exercises and muscle groups (data adapted from Gotschall. 2012)
The EMG measurements Gotschall et al. recorded for healthy college students (10 men, 10 women) suggest that integrated core exercises, rather than isolation movements, are the way to go to maximally stimulate your "abs", your obliques and your lower back. As the data in figure 1 goes to show, not just one, but all of the integrated core exercises shown in figure 2), i.e. (exercise descriptions are quoted directly from Gotschall. 2012) ...
  • Int. Hover with Lateral Arm Reach. Each participant began the exercise in a prone position with the shoulders superior to the elbows, forearms flat with the surface of the floor, shoulders and hips at an even height from the floor, and feet wider than the hips. There [sic!] were instructed to move a single hand laterally from the start position across the floor until the elbow was extended and return to the start position at the cadence of the metronome. 
  • Int. Balance Mountain Climber Plank. The participants were instructed to start with their shoulders, elbows, and wrists aligned from superior to inferior with their feet hip width apart. We provided the cue of flexing the knee to the opposite elbow at the cadence of the metronome and maintaining a flat upper body while twisting the lower body. 
  • Int. Side Hover. Each participant began the exercise in a side position with the shoulders superior to the supporting elbow, supporting forearm flat with the surface of the floor, and feet stacked. We then instructed them to hold the nonsupporting hand superiorly above the head arm for 20 seconds. 
  • Int. Pointer. The participants started in a quadrupedal stance with both hands and knees flat on the surface. We then instructed them to contract their gluteal muscles to lift a single leg and opposite arm to the height of their shoulders at the cadence of the metronome. 
... were superior to their classic counterparts, the isolation crunch, the oblique crunch and, of course, the notorious back extensions done lying on one of those exercise mats.
Figure 2: The integrated core exercises; for a detailed exercise descriptions see text above (img Gotschall. 2012)
The normalized EMS values of the respective target muscles, the rectus abdominis (crunch), the obliques (oblique crunch) and the musculature of the eretor spinae (extensions) were...
  • +225% and +250% higher for the int. hover and the int. m.c. plank than for the crunch
  • +9% higher for the int. side hover than for the oblique crunch, and
  • +66% and +41% higher for the thoracic and lumbar erector for the int. pointer vs. extensions
As you may already have recognized, the additional activation during the side hover, as compared to the oblique crunch, is not only comparably low, the int. mountain climber plank, the int. hover with lateral arm reach and even the standard crunch elicit a +36%, +30% and still +6% higher EMG activitity of the abdominal oblique than the purported "gold standard", trainers in most commercial gyms still prescribe as the "go-to exercise for your obliques".

High EMG values don't equal six-pack abs & 'integrated' exercises  require core stability

Just because the EMG activity that is the electrical potential the scientists measure by the means of surface electrodes is higher for a given exercise than for another, this does not mean that the results you will get from this particular exercise are necessarily going to be superior to those you would see if you performed the 'non-integrated' variety. If you read through the descriptions the scientists give as far as the execution of the exercise is concerned, you may also realize that many of the "spring break warriors" are probably not even able to perform those "integrated exercises" correctly, because they require a non-negligible core-strength to begin with; a foundation, the average Facebook addicted 2012 couch potato is lacking and which obviously cannot be build on the 1000-crunches-a-day people like "The Situation" apparently really believe they had build their abs with.
ChestBicepsBackCoreLegsTricepsShoulders
EMG data for all body-parts -> The SuppVersity EMG Series - Click on the desired body part to see the 'optimal' exercises.
If you can do those movement properly (note: even if you have the strength it will take some practicing to acquire the skills!), fine, do them! If you can't or just started training with your cousin who is raving about the ab-workout he has heard the aforementioned media-personality talk about in one of his YouTube vidoes, you better start (him) out with 'less-integrated' versions of those exercises, such as the "boring"
  • regular plancks, for the rectus abdominis and the obliques, and
  • classic pointers, for the musculature of the erector spinae.
And don't worry, in view of the fact that none of these exercises, advanced or not, are going to shed the flab that may still be covering your muscles, anyways, you and your cousin can, with a clear conscious, take your time, to fortify your core. Not for the next beach season, and not just to build the foundation which will allow you to increase your deadlifts, your squats, your bend-over rows, your pull-ups and all the other movements of which people often don't even realize how much core stability they require, but also and most importantly to be able to walk upright and without pain to the day you depart this life.