Your brain runs on 90-minute cycles. We built a system around them.
The Ultradian Method isn't a productivity hack. It's how your brain already works, and we just stopped ignoring it.
Nathaniel Kleitman found the pattern in the 1950s
The Basic Rest-Activity Cycle runs in phases: warm-up, peak performance, then natural decline across about 90 minutes.
The 15-minute break is not optional
Biology requires recovery to clear stress hormones and consolidate learning.
Six sprints, one day, 7.5 hours of real work
Most people do under three hours of actual work in an eight-hour day. The method closes that gap.
The method works. The method plus a Circle works better.
Peer visibility turns good intentions into follow-through, and keeps the work consistent.