There are two kinds of rest: active rest (where you stay moving, but at a lower effort level), and passive rest (where you stop moving).
In our Total Immersion practice, we might rest the body completely, but we are careful to keep the other systems ready to go. The point of the rest interval is to recover the strength and function of those systems so they are ready to go in the next part of the assignment, and not just go, but improve performance in some way.
To do this, we can guide both our attention and our breathing pattern to support better recovery and better return to our work.
When you come to the wall, or resting point in the swim, you may stop motion of the body, and put it into the most restful position – usually submerged most of the way, until you reach a buoyancy point.
And keep your attention on your breathing. I recommend Nasal Breathing as an excellent way to cooperate with your body’s recovery process and to use this as the focus of your attention.
Though there are good times and reasons to acknowledge the swimmers around you, and even chat a bit, try to avoid doing that in the middle of your practice set. Save it for the breaks between sets. Keep your attention on what you just did, and what you are about to do on this next repeat.