Some fitness experts say: "Your core muscles are probably the most important group of muscles in your body. They literally hold you up. Your core muscles are responsible for your posture, and they are the basis of your strength. Your arms, legs, and head all rely on your core for support and balance."
Huh? For real? I don't know about you, but I think my head, arms, and legs are pretty important. To say that one is more important than the other is like saying the left wing of an airplane is more important than the right.
Basically, the "core" is your torso. Chop off your upper and lower extremities, and guess what? You're left with the core. But remember that your body works as a machine. All the moving parts are integrated beautifully so that you can dance with the grace of Baryshnikov, kick the crap out of the bad guy like Bruce Lee, and do back flips like Nadia Comaneci. The "core" is one important part of many important parts in the human form.
The best way to think of this is to imagine a group of muscles wrapping around the torso. The main muscles include those of the back or posterior.
Posterior Core Muscles: Erector Spinae (large muscles that run vertically giving you a "Christmas tree" effect if you are muscular), Latissimus dorsi (lats), trapezius, gluteus maximus (glutes), etc.
Anterior Core Muscles: Rectus abdominis (six-pack), internal and external obliques, transversus abdominis, and hip flexors.
There is more than one way to work the core. Here are a couple of different options for effectively working your core.
(Note: It may look odd to hold one dumbbell, but think about it: If you hold one dumbbell, it forces the obliques, spinal erectors, and quadratus lumborum muscles to fire in an attempt to stabilize your torso.)
(I once had a teacher tell me that if you do push-ups every day, you'll never have to do another sit-up in your life.)
1. Go to a batting cage and hit some baseballs or softballs.
Think about it: No movement activates the core better than rotating your torso while swinging a bat, trying to hit a ball faster than a teenage girl can scream, "It's Bieber time!"
2. Paddle on a kayak, outrigger canoe, or dragon boat.
Perhaps some of the best and most enjoyable core work involves a body of water, a paddle, and a boat. The rotation/flexion/extension involved in paddling sports makes this a favorite among core enthusiasts.
3. With a training partner, do wheelbarrow training.
This is something you probably tried in grade school. Get a workout partner, grab his legs, and have him walk on his hands. Can you visualize? This is an effective core workout, and it's a blast! Just don't drive your partner's face into the ground. Not a blast.
4. Punch and kick a heavy bag.
Do you ever leave work pissed off? Well, go to a boxing or MMA gym, put on some gloves, and beat the stuffing out of the heavy bag. The whole-body movement of punching and kicking will activate the core like crazy.
5. Do one of the grappling martial arts: wrestling, judo, or jiu jitsu.
Whether you're a fight fanatic or not, the grappling arts will train your core. Just try not to kill your sparring partner.