Our bodies are predisposed to have high mental alertness at 10am, which is after we wake up, and energy levels drop off in the early afternoon until a predictable crash at around 3pm. To maximize productivity during this time, it's essential to plan for a productive afternoon by stopping when you're ahead on a task, setting minor milestones, and working with your energy levels. This can be achieved by using techniques like Hemingway's hack, setting "guardrails of motivation" such as reminders or work sprints, and making progress on smaller tasks. Additionally, incorporating physical activity, chaos, and winding down at the end of the day through activities like writing a letter to tomorrow you can help boost energy levels and set yourself up for success in the morning.