In research reported by the Harvard Business Review, it was stated that very few people could be in a state of high concentration on things that really move the needle forward, like writing about new ideas, for more than four or five hours a day total. This held true even among extremely high performers, including athletes, novelists, and musicians. And, honestly, spending four to five hours a day on high-leverage activities like that is impressive; it’s two hours more a day than average executives and managers devote to building their skills.
