Your core is your torso and is essential to stabilizing your body.
When most people exercise they tend to overlook the core in favor of their arms and legs.
The only time they consider their core is when they look at their drooping bellies and hit the floor to do some sit ups or crunches.
However, the physical fitness of your back and your abs is essential to lifelong health and vigor.
Just think of a tree that exercised its branches but let its trunk get flabby.
Now you see exactly where I'm coming from.
The nice thing about the core is that your back and your abs are really just two sides of the coin and exercises that work one will frequently work the other.
The best exercises to work the core also work other body parts at the same time.
It is really a whole body work out.
This is because your body was designed to work as a whole.
When you lift something your legs should assist your back and arms.
The exercises I am referring to are things like the dead lift, the clean and jerk, squats, lunges, military press and others.
If you really want to work your core like nothing else can you should start using kettle bells.
These are of Russian origin and look like cannon balls with handles on them.
There are hundreds if not thousands of exercise variations you can perform with these.
They work your entire body at the same time but really focus on the core like nothing else.