From NPR: WISDOM FROM THE TOP WITH GUY RAZ
As a young management consultant at Boston Consulting Group, Morten Hansen regularly put in long hours–up to 90 a week. The highest performer in his office, however, was a colleague who clocked significantly less hours and rarely came in on weekends. This experience helped inspire Hansen's research on work and is a central topic in his latest book, Great at Work: How top performers do less, work better, and achieve more. On making a greater impact by doing less.
Morten Hansen is an author and management professor in the UC Berkeley School of Information.