The short version
Sixty seconds, once an hour: eyes onto something far away, three exhale-weighted breaths, shoulders down once. A deliberate pause between demanding efforts rather than running straight through them. For staying fresh across a long day or a long repeated task.
What the research says
Craft, from decades of watching the session players who last. Attention is a budget, and this is how singers spend it.
Rooms where it does the work
Two rules, no exceptions
Never practice any technique on this site while you are driving, operating machinery, or doing anything that needs your full attention. The slow ones can make you drowsy, faster than you’d expect. And never practice a breath-hold, bellows breath, or any vigorous breathing in or near water. Read Before you begin for the doctor’s list and the rest.
The short version is a reminder, not a lesson. The chapter has the story, the steps, the mistakes, and the limits.