Time Management - How Do You Manage Your Energy?

When I first got into the whole productivity space, I was working corporate. So I did the whole time management thing. How do you manage your energy and how do you make sure that you're on point during that time? It's almost like a chicken and egg conversation because you almost need the energy to make sure thatyou're planning your time the right way so that you can manage your energy. And really it doesn't apply just to knowledge workers.