A relaxed and patient swimmer rides the momentum from, first, a good push-off and then from an effective elbow-up stroke. Efficient swimming uses minimum resistance to make the most from propulsive forces.

Every efficient stroke includes a glide phase. Breaststroke, elementary backstroke (rarely used), and sidestroke originated as gliding strokes.

Front and back crawl are really alternating glides on left and right through the front and back. And even butterfly uses a glide when performed most efficiently.

A good glide keeps the body’s “ship” as long as possible as it rides the momentum from stroking, while also keeping the body in position to make the next propulsive effort.

The illustration for this column is not, as many might think, for the front crawl glide position, which is on the side with one arm up and one arm down. It is the glide position only for breaststroke. Even the butterfly glide is different from this, with the arms and hands extended at shoulder width.

The sidestroke glide has the top arm extended along the side. The head rests on the shoulder of the bottom arm, which is extended under water at a slightly downward angle. This prepares for an effective catch and stroke.

Most important, the glide positions for the front crawl and back crawl are just modifications of the sidestroke glide, with shoulders angled slightly toward the front or back.

This not only decreases resistance, but enables the swimmer to initiate a comfortable recovery for the top arm, which in turn leads to an effective stroke, with the bottom arm to the same glide on the opposite side.

Does this apply for competitive swimming? The answer is no and yes. By no, I mean that in competition, swimmers minimize the “ride and glide” aspect of their strokes.

By yes, I mean that all competitive strokes start and finish in the glide position for that stroke, and coaches have their swimmers practice drills that emphasize the “ride and glide” positions. These positions are particularly clear when viewed under water.

The key to becoming a more efficient swimmer is to start and finish each stroke in a glide position that both extends the momentum of the stroking force and also enables the next stroke to be performed effectively.

Dr. Bob Colyer of Bluffton is an actively retired college professor and coach who has recently published “Swim Better: A Guide to Greater Efficiency for Swimmers & Instructors.” bobcolyer@yahoo.com