We work best in natural cycles of 90-120 minute sessions before needing a break. When we need a break, our bodies send us signals, such as becoming hungry, sleepy, fidgeting, or losing focus.

If you ignore these signs and think you can just work through them, your body uses your reserve stores of energy to keep up. It means releasing stress hormones to give an extra kick of energy.

Studies have found we’re actually more effective when we’re stressed. Up to a point.

The right amount of stress at the right time can make us more productive. This requires awareness of your stress levels and how they’re affecting the work at hand.

There’s a simple curve to how email usage affects our productivity. No email = OK productivity. But as we start to use more email, we become more productive thanks to more access to information and collaboration. But this only works to a point.

Once you cross that threshold, more email usage drops productivity to a point where nothing gets done.

How to design the perfect day based on your productivity curves.

• Discover your daily energy/motivation curve. 
• See when you’re hitting your communication threshold. You might want to schedule specific times to check email, like during a break in the morning and again in the afternoon.