Crunch Exercise to Build Lean Muscle in Your Abs

Crunch ExerciseCrunch exercise is one of the best exercises to build your abs and strengthen your core.  It is a great bodyweight exercise that should be part of any overall fitness plan.

They can be done just about anywhere with a comfortable floor, or if you have a workout mat.  You can get a really killer workout in a matter of minutes, and you only need to do the exercise a few times a week.

Remember also that to see your 6-pack really shine, most of the heavy lifting is done in the kitchen, not the gym.  As a general rule, you will need to be around 10% body fat percentage to really see definition in the abs.  So you need to be on a lean and clean diet plan, and watching your calories and portion sizes.

Now, you don’t need to be at 10% body fat to have a great looking stomach and mid-section.  You can be very lean at 15% to 18% body fat, and look great at the beach, in the office, or at your local happy hour.  These crunch exercises will help you to achieve that goal.

Benefits of Crunch Exercise

Crunch ExerciseThere are many benefits to doing this exercise as part of your normal fitness plan:

  • Build and strengthen your abdominal muscles
  • Strengthen your core
  • Improve your lower back health
  • Prevent lower back injury

If you are 35 and older, it is crucial to be aware of your lower back health.  I have suffered injuries to nearly all of my major muscle groups.  Some injuries the result of military training, but most injuries the result of improper workout technique.  As you hit middle age, I can show you how to avoid these injuries and not make the same mistakes that I did.

I have injured my lower back twice, and one instance required months of rehab and two orthopedic doctors.  Both orthopedics advised me that one of the best exercises to strengthen my core (as well as my lower back), was to perform crunch exercises on a routine basis.  I have taken that advice to heart, and it is a priority in my workout routines.

Click here for additional ways to avoid lower back injury.

Performing Crunch Exercise

Crunch exercise is a simple movement, but yet very effective.

  1. Lie on your back with your knees bent and your feet in the air.  Make sure your upper legs (thighs) are vertical.  Cross your arms over your chest or place behind your head.  This is the start position.
  2. Contract your abdominal muscles as you curl your spine into the crunch position.  Your back will arch, unlike a sit-up where it remains straight.
  3. Breathe out as you perform the crunch, and really feel the contraction and tightness in your abs.
  4. Breathe out as your return to the start position.

Reverse Crunch Exercise

This exercise is another good exercise to work your abs, and is just a crunch in reverse.  In the Army we called this exercise the frog kick.

  1. Lie on your back with your legs extended and your arms on ground by your side, with your hands tucked under your rear.  Keeping your legs straight, lift your feet 6″ off the ground.  This is the start position.
  2. Lift your legs and bend your knees until yours knees are over your stomach area.  Breathe out during this motion.
  3. Extend your legs returning to the start position, maintaining your feet 6″ off the ground.  Breathe in during this motion.

Flutter Kicks (Scissors)

Flutter kicks (or Scissors) are a variation of the crunch movement, and also target the abs.
The start position is the same as doing the reverse crunch.

  1. Lie on your back with your legs extended.  Extend your arms down your sides and tuck your hands under your butt to provide stability and support.  Keeping your legs straight, lift your feet 6″ off the ground.  This is the start position.
  2. To perform the exercise, alternate moving your legs in an up and down motion with a range of approximately 12″ for each leg.  I use a 3-count method of counting – 1-2-3-1, 1-2-3-2, 1-2-3-3, 1-2-3-4 etc.

Ab Workout Routine

I like to use a lot of bi-sets and tri-sets with these abdominal muscle exercises.  A bi-set is where you perform one set of an exercise, and then immediately follow it with another set of a different exercise.  A tri-set is when you perform three different exercises without rest in between.  It will generally be a smoker and your abs will definitely feel it.


30 Crunches
20 Reverse Crunches (Frog Kicks)
Perform (3) complete bi-sets with crunches and frog kicks.


30 Crunches
15 Reverse Crunches (Frog Kicks)
10 3-count Flutter Kicks

Perform (2) complete tri-sets, and your abs will feel the love.

All of these exercises work varying muscles in the abs, so this will give you a pretty complete abdominal workout.

Lastly, I always do hyperextensions at the end of my workouts to maintain a focus on my lower back health.  A good lower back stretch at the end of your workout is one of the best ways to prevent lower back injury.  Keep your back active and supple and your back will remain strong and healthy.  Let it go stale and coarse and you’ll suffer from lower back pain.  Live it Lean!

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