Tony Schwartz, author of The Way We're Working Isn't Working (co-authors: Jean Gomes and Catherine McCarthy), says our brains are wired to concentrate for just 90 minutes at a time. Nothing new about that, right? We have gone along this road often.

There is the Time Boxing idea - working on one project only for a fixed, short duration.
There is the 4 minutes of 'rest & stretch’ after every hour of desk work idea.
There is Tim Ferris who tells us to work less and smarter.
There is the fitness idea of running quick, short sprints and resting in between.

Thus, the point: We are not machines.

[From the 100 Ways To Be Being Remarkable Series, a special project that brings you business and self-development advice from The Success Manual. ]