One of my readers has asked me why I downplay kicking so much, except for breaststroke. Good question. Here’s the answer.
In breaststroke (and elementary backstroke), the whip kick is used for propulsion, equal to or greater than the propulsion provided by the arm stroke. Kicking, a scissor kick, is also the primary propulsive force in the sidestroke.
Some kicking is necessary for all strokes. Otherwise, the weight of the legs being dragged will create unwanted resistance instead of maintaining a balanced body position on the surface.
Granted, kicking can add to stroking for competitive swimming. But even then, kicking is more for balance than propulsion. There must be a reason.
That reason is the high cost of energy to kick compared to that of stroking. The general estimate is a 5:2 ratio. In other words, it is two and a half times more tiring for a swimmer to kick hard than to use arms for propulsion.
Thus, in longer distance races, you won’t see much splash or turbulence at the swimmers’ feet until the final stages.
Beginning swimmers use their knees a lot when they kick, mainly to keep their heads above water. This is especially true for the crawl stroke. Experience enables swimmers to be comfortable keeping their heads in the water.
As a consequence, they learn that easy kicking only from the hips requires less effort to keep the body balanced on the surface.
My mentor, Doc Counsilman, used to photograph dogs as they learned to swim. When first placed in water, a dog tended to be vertical to keep its head above water, struggling with all four legs.
Later, that same dog would be using only its forepaws to swim, with occasional use of its rear paws for changing direction. This is a good lesson for humans.
Not only does an easy kick take less energy and provide balance for the extended body, it also reduces resistance by keeping the kick within the path that the upper body makes through the water. If the kick is too high or low or wide, it works against the propelling force of the arms. Most of us are casual or lap swimmers, not competitive sprinters who need extra power over a short period of time.
A minimized kick for the crawl, back crawl, and, yes, even the butterfly is beneficial for several reasons. So, relax and enjoy your time in the water.
Dr. Bob Colyer of Bluffton is an actively retired college professor, coach and author of “Swim Better: A Guide to Greater Efficiency for Swimmers & Instructors,” directed primarily to non-competitors. firstname.lastname@example.org