Every hour of sound sleep yields more than two hours of productive work the next day.
Any athlete will tell you about the value of interval training, where she alternates between a slow and fast heart-rate.
Breaks and vacations help us recharge, making us more productive and effective when we go back to our jobs.
It is easy to forget how rest and high performance are intertwined in a virtuous relationship. Our ability to go to 100 is a function of whether we can go to 0 every now and then.
Observations 