It is no joke that Joe Pilates nicknamed his exercise method Contrology, as in the study of control. While it is easy to mock for sounding so very anal retentive, it is actually a great movement principal to use in most forms of exercise.
Labeled a body / mind exercise, Pilates is about consciously moving your body with control. Haphazard and sloppy movement is a serious no-no in the Pilates method, in both the mat work and when using the machines. Focusing on motions emanating from your core helps you control the movements of your body. Basically you never really get to give into momentum in Pilates instead you control the momentum. You move your body actively and stabilize your core while your limbs move all about.
This movement fundamental can be applied to almost everything. I like to use it when I am lifting weights either free weights or weight machines. Slow and controlled lift up and slow and controlled lowering. If I am trying out a new piece of cardio equipment like the StepMill, I know I have figured out the basics when I can start focusing on this element of control. Step aerobics is another place to finely tune control. Step quietly on the step and you are using control.
Fit's Tip: Being conscious of your body movements while working out is great for injury prevention. Flinging free weights about is a sure fire way to over tax your joints.