Got an adventure trip on the calendar? Maybe you're kayaking the Sea of Cortez, hiking Machu Picchu or climbing Mount Rainier. Granted, you might already be in shape, but taking an adventure trip is akin to doing a marathon: You've got to fine tune your body for the demands of that particular excursion. But how?

You've got a few options. You could wing it, of course, and keep up your regular fitness program (you do have one, right?). You could hire a personal trainer. Or you could a customized fitness plan from Fit for Trips.

Fit for Trips was created by an adventure traveler and personal trainer, Marcus Shapiro, to help people get fit for adventure travels. Shapiro and his team of expert trainers (and they do have great qualifications, by the way) partner with adventure tour operators to create fitness programs for specific itineraries. They also design customized fitness programs for individuals and offer support via e-mail or phone.

Hiking is one of my favorite activities, and whenever I travel, I try to hit a trail. I've done tons of cool hikes around the world -- and some not so cool, including one in Costa Rica that landed me in a cow pasture complete with manure. Here are four of that top my list:

1. Kilauea Iki Trail, Big Island, Hawaii

No trip to the Big Island is complete without a visit to Hawai'i Volcanoes National Park, where you could stand within feet of flowing lava. Once there, drive to the Kilauea Iki trailhead for this four-mile, moderate hike. You'll descend through a lush rain forest until you pop out on the crater floor, which is still steaming. Hike your way across the crater until you spot the trailhead going back into the rain forest, now ascending. By the end, you'll have climbed up and down the equivalent of a 40-story building.

Hot air ballooning isn't exactly a high-energy activity. In fact, you'd probably burn more calories slapping together a peanut butter and jelly sandwich.

Still, though, on a recent trip to Albuquerque, N.M., I couldn't resist hopping in a balloon. After all, every October, the city hosts the Albuquerque International Balloon Fiesta, the world's largest hot air balloon festival. How could I not go for a ride in such a hot air balloon mecca? If nothing else, floating that high in nothing but a straw basket would challenge my mental stamina.

I went up with four other passengers through Rainbow Ryders on a beautiful sunny morning and had a blast. My pilot, Brooke, narrated as we floated over the Rio Grande, dipping so low that we were practically skimming the muddy water. Other times, we floated above neighborhoods -- our maximum height was about 12,000 feet -- where only the barking of dogs shattered the silence. (Don't get me wrong: I love dogs, but I was shocked how loud they were.) The experience was so peaceful and serene (besides the dogs!) that I was disappointed when it ended. Yet I loved the after-flight treat: A glass of champagne.

Multnomah Falls Photo: Karen Asp

I'm in love with Portland, Ore. -- and not just because this ultra-hip, eco-conscious city doesn't have sales tax, which even this non-shopper goes nuts over (hello, lululemon!). Hands down, Portland is one of the best places to take an active vacation. Not only does this area offer dozens of fun adventures, the beauty of the area is also simply stunning. Looking for suggestions on what to do? Check out this four-day itinerary.

Day one: Arrive in Portland, check in at the pet-friendly Hotel Monaco and hop on one of the hotel's complimentary bikes. Then ride the streets, cruising through fun neighborhoods like Pearl District, where you'll find some of my favorite restaurants, including Oba and Andina. Grab grub there at night or ride the fare-less light rail to Old Town Pizza or Kells Irish Restaurant & Pub, two of my other favorites.

Day two: Eat breakfast at the Red Star Tavern & Roast House, next to the hotel, which serves delicious sustainable meals. Then hop in your car and drive the Columbia Gorge Scenic Highway on your way to Hood River. Wear hiking gear, as you'll pass numerous trails on the highway, many of them leading to waterfalls. The most popular? The Multnomah Falls, the country's second-tallest year-round waterfall at 620 feet, which has a restaurant at its base. Hike to the top of the waterfall and then keep going on the trail. Or move on to one of the other dozens of trails along the highway. Once in Hood River, check in at the Columbia Gorge Hotel and watch windsurfers on the river behind the hotel. Hood River is famous for its windsurfing, so if you've ever wanted to take lessons, now's the perfect time. For dinner, head into town to Celilo's for an amazing eating experience. After dinner, take a stroll on Hood River's main street.

A yoga break at the Island Experience. Photo: Courtesy of the Island Experience

Tired of indulging in one too many margaritas and slacking off on exercise during vacation? Then you might love a fitness retreat. Although the length of each retreat will vary, the concept is similar: You'll head to a specific destination where you'll focus on healthy eating and daily exercise. Interested? Check out these five (prices don't include airfare):

If you're seeking an adrenaline rush: the Pinnacle Challenge in Palm Springs, Calif.

This three-day, kick-butt retreat will challenge your inner athlete. Each day, you'll do yoga, hiking, water exercise, weight training and yoga. Meanwhile, you'll indulge in organic cuisine and undergo several fitness tests, as well as educational lectures. The bonus? Two massages. Cost: $1,950 single occupancy or $1,450 double occupancy.

Ana Ivanovic in training. Photo: adidas

Ana Ivanovic fell for the game of tennis when she was just 5 years old. After watching it on TV, she begged her parents to take her to lessons, and the rest, as they say, is history.

Today, the No. 11 seed at this year's U.S. Open (who's also ranked 11th on the Sony Ericsson WTA Tour) can lay claim to several tour titles, including the 2008 French Open. A tough 2009 season and recent injuries may be responsible for her early exit at this year's Open, but she has been working harder than ever off the court to get back into championship form.

Of course, nothing is ever easy as a professional athlete. Not even, you'll be glad to hear, working out! That's what I learned when I chatted with this former No. 1 world player about her fitness program. Two other interesting facts about Ivanovic: She often does Sudoku in the locker room before a match and is superstitious about not walking on the lines of the tennis court.

That's Fit: What are you currently doing to stay in shape? I've read, for instance, that you do long runs, intense sprints and weight training during the off-season.

Ana Ivanovic: That's right. I work very hard during the off-season. I also work intensely during preparation periods during the season. For example, in April before the start of the clay court season, it's important to work on improving the strength in your legs because on clay you need to have a strong, stable base. So I've been working on strengthening my lower body. I also do cardio to maintain my overall fitness, which I think is very good.

Dinara Safina Photo: Getty Images

You know her as the No. 1 player in the world on the Sony Ericsson WTA Tour. (She's also the top seed at this year's U.S. Open.) But what you may not know about Dinara Safina is that she loves watching "Desperate Housewives," she plays soccer, and she has only played her brother Marat, who's on the men's tour, for practice.

Yet the pressure Safina might face if she were to take on Marat for real pales in comparison to what she's facing at this year's U.S. Open. Although she first reached the No. 1 ranking in April 2009, she has yet to claim her first Grand Slam singles title. Can she do it at Flushing Meadows this year? That's a question everybody's asking.

Meanwhile, I had a brief opportunity to chat with Safina about her fitness program. Find out what this top-ranked player had to say -- and why she loves New York City.

That's Fit: How would you rank your fitness level right now?

Dinara Safina: I'm feeling good. I'm working very hard and think I'm in the best shape I've been in.

Photo: mikebaird, Flickr

If you're beach-bound over Labor Day weekend (lucky you!), pack this beach bootcamp workout with you. Exercising on the beach isn't only fun, it's also a great way to challenge your body.

"Sand provides an uneven and shifting surface which makes working out on it more challenging," says Dru Barrios, wellness coach and owner of Ladera Fitness in Laguna Beach, Calif., who designed the following workout. "Your body has to work harder to balance, and as a result, you burn more calories and give that entire body, especially the core, a great workout." There's also less impact on your joints when you do running and jumping in the sand versus hard surfaces, so you're less prone to injury.

To begin, set up two markers on the beach, spaced about 30 to 40 feet apart. Or use landmarks like lifeguard stands. (Try to stick to the hard sand near the water.) Also, keep a water bottle handy. Do a 5-minute walk or jog on the beach to warm up. Then complete the following circuit up to two times, following the modifications if necessary. When you're done, take a 5-minute stroll to cool down.

Photo: Karen Asp

When I was in college, there was nothing a pint of Ben & Jerry's cookie dough ice cream couldn't fix. You name it -- a broken heart, frustrating classes (hello, statistics!), even the afternoon sleepies -- and Ben & Jerry's was my buddy. So when I had the chance to travel to the birthplace of one of my favorite splurges, how could I refuse? Turns out, there's more than ice cream in Stowe, Vt. True, it's a leaf peeper's dream destination, but it's also the ideal location for a little H&W (that's health and wellness in my book). Here are my top six pick for activities to do during a retreat in Stowe:

• Take a hike. Stowe's located in the Green Mountains, which means hiking opportunities are everywhere. But if there's one trail you should hit, it's the Long Trail (catch it at Smuggler's Notch). The trail gets steep near the top and requires some scrambling over rocks and boulders, but you wind up at Sterling Pond, which is stunning.
• Paddle the Lamoille River. Rent a kayak through Umiak Outdoor Outfitters. You'll hitch a ride in a school bus powered by vegetable oil and get dropped off at the put-in spot. As you enjoy this lazy river, you'll cross under four bridges, including a covered one.

Photo: aarmono, Flickr

Travel is one of the biggest obstacles to marathon training. A trip pops up, whether for business or pleasure, and you've got to go. But does that mean you have to bid farewell to your marathon training? Hardly.

I can tell you from firsthand experience that you can train for a marathon from your suitcase. You just have to get a little creative.

For instance, when I did an 11-day Alaskan cruisetour seven weeks before my first marathon -- and this was only one trip of many that summer -- I was a little worried about screwing up my training, but I made it work. On days at sea, for instance, I hit the treadmill and logged the miles. (In all honesty, treadmills bore me to no end, but with my iPod and the incredible scenery, the experience was tolerable, even enjoyable.)

Photo: Portland Marathon

By now, you know I'm a travel hound who will do anything to travel. Even if that means tackling a marathon. Granted, I could do a marathon close to home and spend no time on the road. But half the fun of doing a marathon is escaping to a cool destination. Which is why I decided to tackle the Portland, Ore. marathon two years ago.

Not only is this marathon consistently ranked in the top 10 in the country, Portland is also one of my favorite cities with its tax-free shopping and awesome restaurants. But there's another reason: Portland is the only U.S. marathon to sanction a division in Nordic walking, an activity I'm addicted to. As crazy as it sounds, it's also the Nordic Walking World Championship.

Want to stay fit on the road? Looking for a new active getaway? Let Karen Asp, seasoned journalist, fitness professional and travel addict, give you the scoop on how to take a holiday without packing on the pounds.

Photo: abkfenris/Flickr

I'm a huge snowhound, and Vail, Colo., is one of my favorite mountain towns. Yet as much as I love Vail in winter, summer also rocks, as I find on a recent trip. I hike, rock climb and hit the spas, and then I do something on my bucket list: Whitewater kayak.

I'm actually no stranger to kayaking. I sea kayak frequently where I live in Indiana. Whitewater kayaking, however, is foreign to me so I'm psyched to take a one-day intensive beginner class through Alpine Quest Sports. The only requirement? Be athletic and in good shape. No problem, I think.

I'm a fanatic about working out. I'm a seven-day-a-week exerciser, and rarely do I skip. Until, that, is, I travel, and then my schedule gets out of whack. Occasionally, I'll hit the hotel's fitness center, but that's so boring. Besides, who wants to be trapped in a hotel when there are sights to see? And what if your hotel doesn't even have a fitness center? So here's my solution: Wear a pedometer.

Photo: Karen Asp

Granted, just strapping on a pedometer won't make you move more. (If only it did, though, right?) But it can motivate you to move more, and at the end of the day, it's fun to see how much you've moved without doing "formal" exercise.

For instance, although I did a bike tour during a recent trip to Paris (Fat Tire Bike Tours rocks, by the way, so if you're ever in Paris, look them up), I was mainly exploring museums and churches, watching the French Open and indulging in that fabulous French bread. Was I worried about not doing structured workouts? Not when I looked at my pedometer every night. I logged at least 12 miles every day, some days even more. My reaction? Bring on the bread!