Ride the 90-Minute Wave
Ninety minutes on, then a real break. Ride the rhythm.
Set a 90-minute timer for your next focused work session. Work with full focus for the duration. When it ends, take a genuine 15–20 minute break — not email, not your phone. Walk, stretch, stare out the window. Then start the next cycle.
You have a block of 2+ hours and need sustained, high-quality cognitive output.
The work is inherently fragmented (e.g., support triage) and can't be batched into 90-minute stretches.
Why it works
Your brain operates on roughly 90-minute ultradian cycles. Working with them instead of pushing through produces better output with less exhaustion.
Sustained concentration runs in cycles. Performance rises, holds, then starts to degrade as mental fatigue accumulates. A 90-minute block fits the useful part of that cycle for many demanding tasks, especially when followed by real recovery. Break quality matters. Email is not rest; it is lighter cognitive work that prevents the system from resetting. Walk, stretch, stare out a window, or do something that does not ask for decisions. People who do demanding work often train in focused blocks and recover between them because continuous effort produces less output than it appears to.