Laura Stack writes a great newsletter, not to mention her excellent books. A recent article talked about executive time management, and included this advice:

“Working too many hours is demonstrably counterproductive, because it results in decreased productivity. Studies have repeatedly shown that a 60-hour work week results, on average, in a 25% decrease in productivity. The productivity numbers just get worse as the number of work hours increases.

The lesson here? People aren’t robots. Long hours lead to physical and mental fatigue. This results in slower work, more mistakes, and wasted time. It may also lead to depression, which can spiral out of control if left untreated—which is often the case, because the person affected is too busy to take care of it. In recent years, there’s been an alarming rash of suicides at the C-Suite level. “

Read more: Executive Time Management: How Time Management Changes as You Move from Middle Management to the VP/C-Suite Level