It definitely says "breathing" here, not "breath," so definitely not Atem, but rather Atmung or Atmen. Maybe the surrounding context gives some clues as to how it's intended (it's not clear in the E., either).
Consciousness no doubt has something to do with it, but not in the yoga or meditation senses.
The OP seems to refer to breathing as a physical act, a fact we easily lose sight of---breathing just goes on in the background---to becoming aware of that, and to consciously (re)connecting it qua physical act with the body (its sensations, its movements, etc.).
Here's one (admittedly yoga-oriented) online use of "verbinden" which preserves the vagueness of the E.: Indem wir unseren Körper mit der Atmung verbinden und bewegen, beginnen Energien zu fließen. Wir lernen unseren Fokus achtsam auszurichten und das ...