Your ultradian rhythm cycles every 90 minutes—focus peaks, then dips. Push through and you're working at half capacity. The fix: work in 90-minute sprints, then take a real break. No email, no scrolling. Walk, stretch, stare out a window. Your next sprint will thank you.

One task. No interruptions. Timer set. When it rings, you stop—even if you're in flow. The break isn't optional; it's where your brain consolidates what you just learned.

During rest, your brain replays patterns at 20x speed. That's why solutions appear in the shower. Skip the break and you rob yourself of the insight. Treat rest as seriously as the sprint—schedule it, protect it.

1. Pick one deliverable. 2. Close all tabs, silence phone. 3. Set a timer for 90 minutes. 4. When it rings, stand up and move for 15 minutes. 5. Repeat. After 3 sprints, take a longer break. You'll get more done by 2pm than most do all day.

Every interruption costs 23 minutes of refocus. That's why the sprint must be defended. Put on headphones, close your door, use a 'do not disturb' sign. Your future self will thank you.

Three sprints a day = 4.5 hours of deep work. That's more than most people manage in a week. The secret isn't more hours—it's better hours. Start tomorrow: block 9–10:30am, 11–12:30pm, and 2–3:30pm. Watch what happens.