A prevalent philosophy exists in certain spheres that succeeding in business means putting in long hours and being willing to forgo niceties such as leisurely weekends or untethered  vacations. But overwork--arriving early, staying late and checking in after hours--is actually counterproductive and leads to burnout, low morale and health issues. That's according to Mercedes DeLuca, COO of Basecamp, who says the project management software company holds to a strict 40-hour workweek and even has a campaign asking other companies to sign its "Work Can Wait" pledge. Here's DeLuca's thinking on the subject.

1. Very little of your work is life or death.

Think about your deadlines. Are they arbitrary or self-imposed? Does your work really need to be done right now, before the end of day or in a rush? Can it wait until tomorrow, or the next time you show up at the office? Chances are, it can.

2. A 40-hour workweek is the humane way to conduct business.

The best businesses care deeply about their customers. It only makes sense to treat the people serving them--your employees--in the same manner. It's about demonstrating internally what works externally: Respect, kindness, empathy and good manners. "You want to treat customers with humanity," she says. "But the reality is that if you don't treat your employees with humanity, it's pretty hard to get that translation.

3. If your work truly can't wait, do it right away.

If it's truly urgent and critical to your business, do it first and get it done. "Those are the exact things you should be focused on," she says.

4. Focusing on meaningful work increases employee satisfaction.

If employees use their 40 hours focusing on the things that really matter, they will be doing meaningful work, which naturally leads to engagement and fulfillment. "I try to front-load my day with the things that matter the most to Basecamp," she says. "And a funny thing happens when you get those off your plate--you immediately feel like ah, I really got some good work done today."