He opened a timer app and set it for 60 minutes. “Tomorrow, I want you to try something. Work in 60-minute blocks. But here’s the secret: every 60 minutes, you stop completely for 5 minutes. No email, no calls, no ‘just checking one thing.’ Walk away. Stretch. Hydrate. Stare out a window. Then come back.”
To ensure you can hit 60 minutes again tomorrow: 60 minutes stamina