Distance per Cycle and Cycles per Minute  

"There are only two direct affects on speed.  One is distance per cycle, and the other is cycles per minute. Those are the only two choices you can use to affect going faster or slower, or staying the same." 

The distance per cycle or stroke length, achieved by the swimmer when swimming freestyle, backstroke and butterfly, will depend on the anchoring quality on which you slide the body forward, and the force that is developed by the body core and hip rotation (freestyle and backstroke, but in butterfly there is no hip rotation). 

The arms should anchor the body at the catch, then using the body core and hip rotation to provide force upon the arm; the body is slid forward over the arms. 

Body position on the side is a major factor in attaining maximum slide and distance per cycle, due to reduced water resistance in that position.

Depending on the efficiency of the movement there will be a degree of slip, but this concept must be taught. The instruction should be to teach these skills, the training is simply the practise of those skills at the appropriate speed.

If you look at technique at various points on the speed curve you will find that there is a change, so that you cannot take just one point in the curve and say ‘that is how you swim,’ and then work on that. Both cycling rate and distance per cycle change.

 Technique is specific to the speed at which it is done so the swimmer will have to learn to make choices, and practise the intended technique or changes in technique at speeds that will be swum over the various distances.

 Also, as muscles adapt exactly to what is the predominant stimulus to which they are exposed, maximum fitness also requires predominant emphasis on race pace training. 

Very often this type of training is left until late in the training cycle which is a mistake; as muscle adaptation to speed-fatigue resistance, which is the most important aspect of training, is delayed and incomplete.