Mix Fitness's Blog

Upper Abs vs. Lower Abs

Posted in Uncategorized by mixfitness on March 8, 2010
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How many times have you heard someone say, “You’re working your upper abs when you do crunches?”  It leads you to believe your “lower abs” are doing nothing during a crunch, right?  It also sounds like you have two separate muscles.  Well, that statement is a misnomer.

You don’t have “upper” or “lower” abdominal muscles.  You have one long muscle called the rectus abdominis.  It’s the same muscle that is nicknamed the “6-pack.”  This muscle runs from your ribs to your pubic bone.  Take a look at the picture.  Locate the belly button.  Do you see the dark lines just to the right and left of the belly button?  That outlines the rectus abdominis muscle.  Notice how the outline starts just below the pecs (chest muscles) and continues past the belly button into the crotch.  (Sorry, but that’s how low this muscle goes!)  

Now, lay on your back to prepare to feel for yourself the inaccuracy of the above statement.  Place one hand behind your head and the other on your stomach, a couple inches below the belly button.  Do a few crunches.  Can you feel the rectus abdominis contracting under your hand?

When you do crunches, your entire muscle contracts.  Similarly, when you do reverse crunches – typically to target the “lower abs” – the entire muscle contracts.  Yes, the upper fibers will fatigue after several reps of crunches.  But, know that the whole muscle was worked.

I’m being nit-picky about the usage of the phrase…I know.  But, this phrase has led to misconceptions.  Next time you hear it, realize what he really means is, “When you do crunches, you’re working your rectus abdominis completely, but you’ll feel it more in the upper portion.”


The “Core”

Posted in Uncategorized by mixfitness on July 20, 2009
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If you’ve attended a group fitness class recently, you probably heard the instructor say something along the lines of “let’s work the core,” or “tighten your core.”  I say these things too.  But, what exactly does it mean?  What do you do when you’re instructed to use your core?  Today’s blog is to help you answer those questions.

As a fitness professional, I’ve heard a number of definitions for the core.  One personal trainer defined the core as “everything from the pits to the hips.”  A yoga instructor stated that the core starts in your feet.  So, there are many interpretations for what the core encompasses.  In general, the core is the mid-torso region….not just the abs.  Furthermore, the abs are more than one muscle – more than the 6-pack.

The core is sometimes referred to as the “powerhouse.”  This is because strength and power for any movement truly starts in the core.  Athletes have amazingly strong cores for better performance, not for looks.  You golf better, balance better, squat better, move better, when you have a strong core.  Let’s talk about which muscles make up the core.  My definition is the abs and low back.  Quick anatomy lesson:  there are four muscles that are the abdominal muscles.  They are the rectus abdominus (which is your 6-pack) internal obliques, external obliques, and transverse abdominus (TA).  Your obliques rotate your torso.  Your transverse abdominus is deep inside and wraps around your torso.  When group fitness instructors say “engage your abs” or “tight core,” they really mean contract your TA.

So, how do you contract your TA?  A pilates instructor will tell you to draw your belly button to your spine.  It’s a small, but visible movement.  And, it’s very different from sucking in to button tight pants!  I like to have my clients identify how it feels when their TA is activated.  To do this, I have them standing with their arms straight at shoulder height, palms touching.  Then, I say “don’t let me move your arms” and try to push their arms to one side.  Try this with someone and feel how your insides, your TA, has to tighten to prevent your arms from moving.

It’s important to train your lower back muscles when training your abdominals.  This promotes not only a healthy back, but also a healthy core.  The abs and low back work together.  One can’t function well without the other being strong.  So, if you do crunches, also do back extensions or “supermans” as they’re usually called.  Planks are a great core exercise as long as you are using your TA.  Next time you are lifting weights, be aware of your TA and if it’s working.  You should feel the difference!

If you have questions about the exercises I mentioned above, please leave me a comment!