People plan vacations over months or even years. They sink dozens of hours into finding the perfect hotel, the best restaurants, the cheapest airfare, and, of course, that just-right destination. Vacations form a keystone of the economy; while the passengers in first class might be traveling for business, most of coach is headed somewhere for kicks: in fact, 75% of domestic trips, more than 1.7 billion of them, were for leisure purposes. This means that 1.7 billion times in 2014, vacationers came home from a week-long trip or a two-day trip and had to fend off the stress, lethargy, and sadness that beset the post-vacation traveler. The week after vacation is decidedly not awesome.

The doldrums that can set in after a ski trip or another vacation are a common and real enough phenomenon to be recognized by doctors and the medical establishment. Whether it was after that week-long family vacation in Cabo or that week of skiing at Keystone, readjusting to real life after a trip can beat down even an optimist's psyche. But there exists hope for travelers. We want our readers to be able to bounce back from whatever trip they take, be it skiing, beaching, golfing or whatever, so we did the research and talked to the experts who offered thoughtful advice on how to make that first week back from vacation as invigorating as that week of anticipation before the trip.

Here's some of the best advice we found for keeping that vacation glow and avoiding a spiral into the post-vacation blues.

Before You Leave
Cracking the code to avoiding that post-vacation letdown starts before you happily hop into that taxi. You'll be best off with some pre-trip work and planning to make sure that once you get home you're not thrown back into tight deadlines, thousands of emails, and no home time to debrief mentally, emotionally and physically.

So this is what you need to do: as tempting as it may be to let that vacation excitement help you skate through the pre-vacation work week, don't. Get your work done. Set goals for yourself and hit them. Working hard during this last week should be easier than it is normally, with a sunny beach or snowy slopes in your future. Not only will it cut some of that stress from your vacation and make you feel like you really deserve that time to relax, but it'll make coming home easier without heading full speed into a tight deadline.

Once You're Home
Perhaps most important: Give yourself a day or two once you return home. When I was growing up, I absolutely hated this. We always came back from weeklong vacations on Friday or Saturday before heading back to the real world on Monday. Every year, I was bummed to be going home, when we could be spending another day or two in paradise. Why shouldn't we spend as many days as possible on vacation? But that was a child's perspective; I see my parent's wisdom at work now. Maximizing time spent on vacation might minimize sleep and just increase your stress levels when coming home.

Not the place you want to be if you have to be in the office the next day.

Those one or two days of doing nothing at home before going back to doing everything at the office can be a salve for fending off those post ski-trip blues. These lazy days needn't have many expectations: hit the grocery store, unpack the suitcases, do a few loads of laundry. Not only will this reintroduce your routine but by getting the shopping and laundry done before the work week stress hits you, you will no doubt reduce stress later in the week. And because post-travel exhaustion can so easily lead to post-travel downs, this time is crucial for physical and emotional refueling. Catch up on some Zs in your own bed and go for a run if you're feeling ambitious. These cozy days will remind you why it's good to be home: home doesn't involve delayed flights, outrageous fares or uncomfortable mattresses (we hope).

Next, try not to let this vacation be it for the year. Saving up those vacation days for one big trip may seem like a good idea-the trip will no doubt be relaxing and immersive. But coming back to the realization that you've nothing similar to look forward to for six months or more is a brutal way to wake up to Monday morning. The experts all recommend that a great way to keep the post-vacation letdown at bay is to plan another trip as soon as you get back or at least to begin to think of what's next. Anticipation is proven to make us happy. In her article for the New York Times, Stephanie Rosenbloom writes of this effect, citing a 2010 study that examined the connection between anticipation and happiness. "Wish you were on vacation right now? Don’t," Rosenbloom wrote. "Taking a vacation won’t necessarily make you happier. But anticipating it will." The data, she argued, show that vacationers are found to be most happy before their vacations.

So start surfing the web and looking for your next getaway even if it is months from now. That anticipation just might get you over the back-from-vacation down period that plagues us all. And that next trip needn't be a week-long, lavish affair. A low-key, low-cost Saturday outing can also generate those positive vibes and it rewards yourself for getting through your first week back. So think about things like hitting the slopes at your favorite local mountain, grabbing tickets to a game, or heading into the city for a comedy show. Plan something out of the ordinary (and low stress) to give yourself something to look forward to immediately.

Dr. Katherine Loflin told us the same thing, too, saying that travelers should attempt to "blur the lines between vacation experiences and your hometown experiences. What is it about the vacation that you really love or feel like you are losing when you return home?" Freedom, time, discovery, rest, good weather? A wonderful combination of the five? Whatever it is you won't be able to replicate it once you're home. But that doesn't mean you can't try to provide your daily life with some of things that make vacation so great.

This scene doesn't have to be relegated to vacation only

"Discover something new about your place," Loflin says. "Find a hidden gem or quiet retreat in your hometown. Take the feelings with you when you come home so you don’t feel so jolted back to reality." Find that Mexican restaurant that serves similar cuisine to what you were happily feasting on the week before. Take pictures of the amazing places and views close to home and share them on Instagram just like you did on vacation. Not only will this bring you back those wonderful feels from your vacation but it will help you see how your life at the beach, on the slopes, or on the road doesn't have to be so separate from your life at home.

Leah Roche is an associate producer at ZRankings. Find her on Twitter here.