Experts believe that the great performances of world-class swimmers are approximately 70 percent determined by the efficiency and economy of their body position and stroking movements, and only 30 percent by their power and physical conditioning. For the less experienced and less skilled swimmer, perhaps 90 percent or more of your performance is determined by how efficiently you move through the water. Less than 10 percent is determined by how fit you are. But very few people work at swimming that way. However, simply acknowledging that better technique is the way to swim faster still doesn't get you completely out of the woods.
Many swimmers work on technique for months or years, but still see little improvement.
This is because their attention is on things that have little effect on their performance. An analysis of races at the U.S. Olympic Swimming Trials in 1984 and a separate study of the swimming events at the 1988 Olympics in Seoul concluded that faster swimmers consistently took fewer strokes than slower swimmers. There are two ways to make that happen. The most obvious is to develop a more powerful stroke that will thrust you farther down the pool with each pull. However, few swimmers focus on that as a way to improve.