Some people will bristle at the seemingly oxymoronic notion of a “productive vacation.” But as an entrepreneur for the past decade, if I’m going to take a vacation at all, it needs to be productive — otherwise, without the safety net of paid vacation days and coworkers to cover for me, I might as well keep working. That’s not to say I don’t take lengthy, enjoyable vacations; I previously wrote for HBR about my month-long, unplugged sojourn traveling in India. But we all have limited time off, so we have to choose wisely. Here’s how I balance having a productive yet refreshing vacation.