On the TI Discussion Forum, Barton wrote:

In a recent thread Coach Eric DeSanto gave me some great advice on not sinking while I breathe: “Finally, check the speed of your recovery. If your tempo and recovery are too slow, you will sink as your arm is out of the water.”

Also on the Forum, Coach Eric DeSanto replied

Barton,
I am still playing with the idea to figure out what I believe works for me, but here is my current thinking:

1. I started trying to speed up the recovery when watching elite swimmers — Phelps, in particular. I noticed that they seem to spend a much higher percentage of the stroke cycle with both arms in the water.

2. When I first mentioned this on the Forum, Terry said he prefers to make the recovery more compact rather than speed it up. More compact means less distance to travel so the effect of keeping both arms in the water is the same, but you don’t have the acceleration.

3. I believe that the recovery arm has usable momentum. If you use the weight of the arm with its speed, it will drag you forward after the spear.

4. The risk of course is that the faster the recovery is, the harder it is to have a clean entry and perfect timing.

A good approach for any change you’re considering is “try it”. If you speed up your recovery, and it helps your pace, stroke count, or overall ease, then keep it. If it hurts any of these, drop it. There are probably differences in the people’s bodies that favor each recovery speed.

I added these thoughts:

The choice between faster and slower movements is one that is challenging to make in a way that improves your swimming. Your question mentioned that slower recovery led to sinking. That suggests the issue may be balance, rather than recovery speed. The better your balance, the more choices you have about many aspects of your stroke – including a slower recovery. How might a slower recovery benefit you?
1) It allows you to remain in your most-streamlined position (aligned from fingertips to toes while rotated just off your stomach) slightly (and by this I mean just milliseconds) longer in each stroke cycle. This means you’ll travel farther faster during recovery.
2) Holding this position slightly longer also gives you more time (again, milliseconds) to arc your fingers down to a palm-back position, while rotating your elbow up and out to trap water behind your forearm.
3) With your hand and forearm positioned to maximize purchase, you’ll propel yourself farther and faster on your next weight shift. Better balance and a slower recovery allow you more time to examine and optimize that aspect of stroke timing.

If a lower-drag body position and a higher-traction arm position mean you’ll swim better and faster, then you’d want to maintain them at any speed.

Having established the potential benefits of a slower recovery, let’s examine the potential benefits of a faster recovery. I can see two:
1) Faster Stroke Rate and
2) Longer “wetted” time for the arms – as Eric mentioned above. An arm above the water adds weight to the body — downward, rather than forward, energy. A wetted arm adds length to the body — reducing drag and conserving forward momentum.

Aiming for a Faster Stroke Rate gives you a better chance of converting effort into speed. Aiming for a Faster Recovery doesn’t. Stroke Rate is the sum of many inputs. The most critical is how quickly you can create the hand/forearm position I described above. So my choice would be to focus on increasing SR, as a whole, rather than to isolate and speed up the recovery. I would do this in increments of a hundredth of a second with a highly precise tool — the Tempo Trainer. (And you may find that small increases in tempo help your balance.)

To increase “wetted” time for the arm, rather than try to move my hand forward faster, I’d seek to follow the shortest path from exit point to entry point. I do this in two ways:
1) Convert a wide-swinging path from exit to entry point to a laser-straight path. I do that with the Draw a Line exercise and focal point illustrated in Lesson 5 of the Easy Freestyle DVD.
2) Convert a high-swinging path from exit to entry point to a surface-skimming path with the Ear Hops exercise and focal point, also illustrated in Lesson 5.

Finally, I want to emphasize that I do agree with Eric’s idea that a faster recovery can help increase forward momentum. It takes a high degree of skill to convert faster recovery into faster swimming. The Tempo  Trainer offers a controlled way of experimenting with it.