I recently ran across an article in the August issue of Competitor magazine titled "10 Commandments of Swimming" and subtitled "Swimming Gods from Across the Country Share the Top-10 Laws for Increasing Your Efficiency in the Water".  Here’s Commandment 4 from the article:

Thou Shalt Not Decelerate
If you’ve ever been kayaking, you know that as soon as you complete a paddle-stroke on one side, you should immediately begin a paddle-stroke on the opposite side. Doing this keeps your kayak moving forward and minimizes deceleration.  "learn to elongate your reach – your arm’s extension and entry into the water – and precisely time the catch with the end of the propulsion phase of the pulling arm,"…"In other words, there should be little, if any, deceleration and glide".

Let’s examine this "commandment" in light of what we know about kayaking, swimming, and common sense.

1. Favor Streamlining over Power
The front of a kayak doesn’t disappear between paddle-strokes!  The length and shape of a kayak determines its potential speed.  The longer and more streamlined it is, the less it will decelerate between strokes.  A swimmer, however, loses some of that length when the lead arm begins to pull.  Until it is replaced by the other arm, the bodyline becomes shorter, and therefore less streamlined. 

We can minimize deceleration in two ways:  continuously apply power, as the article suggests, or leave the lead hand in place a bit longer to reduce drag.  The first method requires a higher stroke rate and more power (because you’re propelling a less streamlined vessel, you have to apply more power to overcome drag).  The second method decreases drag and allows you to swim faster with less power.

2. Reach Through the Water, Not Over It
Elongating your arm’s extension and entry into the water does nothing to propel you forward. It requires energy to support your arm out of the water as you reach forward.  And it reduces the amount of time you spend in a longer, more streamlined body position.  Then, after your arm enters, it’s pressing down on the water, which requires energy, and pushes the hips down.  Worst of all, it puts the shoulder in a weak and vulnerable position, setting you up for injury.

Instead, let your hand enter the water closer to your head, and then make your extension happen underwater.  Allow the water to carry the weight of your arm from entry to extension.  This will make you more streamlined, save energy, and help to protect your shoulders from injury.  As an additional bonus, this type of entry can concentrate energy from the body’s weight shift and direct that energy forward.

3. Don’t Windmill!
Timing your catch with the end of the propulsion phase (a wind-milling stroke) again shortens your vessel, making you less streamlined.  Further, it fails to capture the energy released by the weight shift as you line your body up on one track, and then the other. 

This is also guaranteed to increase your stroke rate and decrease the distance you travel with each stroke. The formula for speed in swimming is Stroke Rate (SR) times Stroke Length (SL).  Wind-milling increases stroke rate.  Increased SR is a good thing, provided that your fitness will accommodate a higher stroke rate, and your coordination enables you to travel a sufficient distance with each stroke to make the formula work in your favor.

By training SR alone, you can make physiological adaptations (become more fit).  However, you are likely to lose SL and end up swimming no faster, perhaps even slower. Instead, swim with the purpose of maintaining Stroke Length while you gradually increase Stroke Rate.  You will swim faster while imprinting the stroke habits required to be more efficient. You’ll still gain fitness as you extend your ability to swim farther and faster.

4. Gliding = Less Drag
The last sentence offers a false choice between minimizing deceleration and glide.  By optimizing the time we spend in a long bodyline, we can minimize deceleration and increase stroke length (glide).  Total Immersion swimming helps you develop the technique to travel farther and faster with each stroke, rather than wind-milling to a shorter stroke with more effort. Minimize deceleration and increase glide!