Looking at the basic elements of a golf swing, an effective efficient golf swing has to be a 'stable on-plane force' thats delivered through impact. The most efficient golf swing motion is a rotational pulling force.
Through bio-mechanics we know that when muscles contract/shorten it creates a 'pull' on the bone that the muscle tendon is attached, this produces movement, velocity.
These muscle actions are called concentric control. the opposite, so deceleration of motion is controlled by the muscles 'lengthening', eccentric control.
In a golf swing that's a ways effective there are these 'pulling forces' (the shortening of the muscles involved) through impact that are applying and aligning force down into the ball.(pulling - as the hands always pass the ball before impact, before the club head)
The muscles work in pairs, 'agonist' and 'antagonist'. So when one muscle shortens or 'pulls' it causes its paired to relax and lengthen, shortening or 'pull' happens first in the sequence causing the antagonist muscle to relax and lengthen.
So when the 'mass' of the golf club is 'pulled' effectively the body's muscle system involved in the motion is shortening and lengthening pairs of muscles.
Distance is all about the most efficient on plane force at impact.
So it's about the 'shape' of the swing & the sources of that force.
The shape of the swing, swing plane, if the club is on it's natural plane, the swing can then happen with almost no compensatory motions so the club stays virtually parallel to the angle the shaft occupied at address through impact. (any compensatory manipulations during the swing causing it to leave plane will effectively slow it's moment through the swing to impact, less speed than could have been produced through impact than if it had stayed on plane.
The swings sources of power/force/speed, is greatest when the clubhead is staying behind the golfer's hands through impact (pulling forces), then efficient force, and not effort becomes the swings source of power. (hence why the majority Tour golfers swings, the ones that do all this most efficiently, make it appear to be so easy to do)
So to 'get' more speed, you first have to improve the shape of the swing, the balance & timing in a correctly timed sequence of motion in order to achieve the optimum force/power so speed through impact to transfer most efficiently the most energy to the ball to produce greatest distance possible from the swing.
