Danny Way explains: “It’s either find the zone or suffer the consequences — there’s no other choice available. - Steven Kotler

The point at which someone goes into REM is a fantastic indicator of depressive tendencies,” said Britton. “We’ve gotten very good at this kind of research. If you took 100 people and did a sleep study, we can look at the data and know, by looking at the time they entered REM, who’s going to become depressed in the next year and who isn’t.” Normal people enter REM at 90 minutes. Depressed people enter at 60 minutes or sooner. It works the same in the other direction. Happy people go into REM around 100 minutes. Britton found that the vast majority of her near-death group entered REM sleep at 110 minutes — a rating that is nearly off-the-charts for overall life-satisfaction and a neurophysiological correlate that supports the anecdotal evidence that these strange states are literally and completely transformative.

Treat fear like a playmate,” suggests Ulmer. “This transforms the emotion from a problem to be solved into a resource to be savored.

The past three decades have witnessed unprecedented growth in what researchers now term ultimate human performance. This is not the same as optimal human performance, and the difference is in the consequences. Optimal performance is about being your best; ultimate performance is about being your best when any mistake could kill. Both common sense and evolutionary biology tell us that progress under these “ultimate” conditions should be a laggard’s game, but that’s not exactly what the data suggests.