Making It Work in Reality

The biggest objection to 90-minute cycles is "I cannot block my calendar like that." Start smaller: protect just one 90-minute block per day. Mark it as a meeting with yourself. Turn off notifications. Tell colleagues when you are unavailable.

Do not aim for perfection. Some days, interruptions will break your cycles. That is fine. The goal is not rigid adherence but a general rhythm that your body and brain learn to expect.