Here's the conundrum when it comes to free time: Do too little exciting stuff during yours and it tends to become an undifferentiated blur, leaving you feeling like your weekend passed in a pointless flash. Do too much and you come back to work on Monday feeling like you need a weekend to recover from your weekend.

So what's the Goldilocks point? How much excitement should you schedule to make your time away from work as refreshing as possible without tipping into the overwhelmingly frantic? Science can help you walk this tightrope.

The science of spontaneity versus scheduling

First, it's important to understand a few relevant studies. According to one recently published piece of research highlighted by the Washington Post, for instance, scheduling your free time strictly can make it anxiety-producing rather than relaxing.

"The paper argues that when a leisure activity is planned rather than spontaneous, we enjoy it less," states the article. "That's because we tend to mentally lump all our scheduled activities in the same bucket -- whether it's a dentist appointment or grabbing coffee with a friend."

"It becomes a part of our to-do list," study co-author Selin A. Malkoc comments. "As an outcome, they become less enjoyable."

On the other hand, there is also scientific reason to suspect that chilling with Netflix all weekend is going to end up being a relaxation bust too. Research shows that when we experience novel things and form new memories, time slows down. That's why the days seem to pass so slowly when you're a kid and experiencing so many new things (and, sadly, also why it flies when you're older and the world becomes old hat).

Various time-use experts have picked up on this truth to argue that the best use of your free time is plenty of preplanned and challenging activities -- think less slothful lounging and more mountain biking and volunteering. "Other kinds of work--be it exercise, a creative hobby, hands-on parenting, or volunteering--will do more to preserve your zest for Monday's challenges than complete vegetation," author Laura Vanderkam has written.

How to strike the perfect balance

So how do you balance these two competing lines of thinking -- avoiding the happiness-destroying stress of the thoroughly scheduled weekend, while also dodging the memory-busting effects of spontaneity and sloth? Malkoc (of the scheduling-leads-to-misery study) thinks she has the solution.

"The answer, according to Malkoc, is 'rough scheduling,' meaning meeting for lunch or an after-work drink but not assigning it a time," reports WaPo. "As trivial as the change might seem, it has an important effect on human psychology: It reintroduces the flexibility to the leisure tasks," says Malkoc, explaining the thinking behind the idea.

But wait, you might object. My friends are already totally flakey. If we don't set a time for a thing, it's likely that it will never happen. Don't fret, replies Malkoc. Bailing on activities isn't always a terrible outcome. "If things don't work out, in all likelihood at least one of the parties was forcing themselves to make it happen -- and thus would enjoy it less. So, maybe things worked out for the best," she points out.

The bottom-line advice here is that while doing nothing is no way to refresh yourself on the weekend, scheduling leisure like you do a meeting with your boss isn't a good solution. Instead, strike a balance between spontaneity and scheduling. Agree to a few key activities ahead of time to give your free time some structure, but also give yourself the wiggle room to set the time (or cancel entirely) on the day. You'll get the benefits of active free time without the brain-frazzling effects of thorough scheduling.