Conventional wisdom tells us that well-defined abs are formed by performing weight exercises and crunches.
While that’s true to a degree, cardio is an often-overlooked component of achieving a flat stomach. Any continuous activity that increases your heart rate will do—but what better activity than running?
There are four types of abdominal muscles: the rectus abdominis (the six-pack muscle), the internal obliques (inner sides), external obliques (outer sides) and the transverse abdominis (the deepest of the four muscles which runs around the abdominal region like a corset).
All four muscles need to be worked in order to reach peak abdominal strength; however, cardiovascular exercise is needed on top of that in order to get the most eye-popping results.
In order to engage your abdominals during your run, orthopedic surgeon Dr. David Neuman and physical therapist Karena Wu—authors of Pop-Doc, a postoperative book of exercises (and website) that helps people recover from joint pain—recommend focusing on your transverse abdominis (the deep core muscles) for maximized results.
Running automatically engages these muscles, which help stabilize your spine and reduce the impact forces that occur in your joints. To strengthen the core even more, hold your belly button into your spine while running, without holding your breath. This will tighten the core and power up your limbs. It will also give your abs that nice definition along your side.
Engaging the transverse abdominis has the added benefit of protecting the spinal column from the natural forward bending motion that occurs with each step during a run. That bending motion, meanwhile, furthers your core flexion and definition.
Running is the highest impact sport because there is a period of gait, in which no part of the body is in contact with the ground. As soon as one foot hits the ground, all muscles simultaneously contract, which means all get a little strength and endurance workout at the same time.
What that means for you, the runner? More fat is burned faster, and your rock hard abs are more visible.
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