all the above being said plus if you make sure you keep your arms in to your side, push your forehead into the camera, hold it with your hand securely under the lens, stand with your feet a part ( kind of so you make an a shape to steady yourself) it might help. i notice if i try to be more careful about my technique i have better longer zoom shots, everything else being equal. if i rush a shot i usually end up blurred.
if you are talking about the on camera flash i don't think it would help freeze the action for that length is that is what you are trying to do