Jim Loehr — American Psychologist

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Even if you're ill, physical activity at a lower level will help you beat it.
Boundary setting is really a huge part of time management.
It's not how many hours you put in with a client or on a project. It's the quantity and quality of your energy - your focus and force - that determine whether that time is valuable.
The most important asset you need to protect in order to manage the demands of a job or an investment portfolio is your production of energy. And, just like with money, if you do a great job managing your energy, you'll get a great return.
When people are entering a high-stress period, they don't sleep and don't exercise, but in fact, it should be just the opposite.