In the 1950s, the researchers William Dement and Nathaniel Kleitman discovered that we sleep in cycles of roughly 90 minutes, moving from light to deep sleep and back out again. They named this pattern the Basic-Rest Activity Cycle or BRAC. A decade later, Professor Kleitman discovered that this cycle recapitulates itself during our waking lives.
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In each of these fields, Dr. Ericsson found that the best performers typically practice in uninterrupted sessions that last no more than 90 minutes.
Uninterrupted work sessions of 90 minutes are not a cycle, since they don't include a rest phase. It may be that 90 minutes is an optimal number for uninterrupted work, but I don't understand how it relates to a "Basic-Rest Activity Cycle" of 90 minutes.
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In each of these fields, Dr. Ericsson found that the best performers typically practice in uninterrupted sessions that last no more than 90 minutes.
Uninterrupted work sessions of 90 minutes are not a cycle, since they don't include a rest phase. It may be that 90 minutes is an optimal number for uninterrupted work, but I don't understand how it relates to a "Basic-Rest Activity Cycle" of 90 minutes.