With long flights, decadent foods, and little time for the gym, traveling can take its toll. How can you avoid the nasty flu going around and stick to your New Year's Resolution even when you're in and out of airports or on the road? We asked three guys who travel for a living for tips for staying fit while still enjoying your trip.

Andrew Evans, National Geographic's Digital Nomad, gets paid to travel the world exploring and to share his experiences through social media and blogging. He traveled 276 days in 2012, and expects to hit the same number this year. He averages one airplane and one new country per week.

Unplug to unwind. Shut off all your gadgets, turn off the TV screen, drink a glass of water, put on a face mask, stick in ear plugs, breathe deeply, meditate, and then go to sleep, he suggests. "I rarely use any sleep aids because I don't like feeling groggy," he says. "I find if I've done some intense exercise before a flight, it helps me sleep."

Improvise. When there's no gym at his disposal, Evans takes advantage of what's around. In hotel rooms he does dips with the chair and bed, arm curls with his packed suitcase, and pushups and situps daily. (Try this Hotel Room Workout you can do with your carry-on luggage.)

"When all else fails, you have to be inventive and determined," he says. "I do pull-ups on tree branches or on the exposed water pipes in the hotel basement. You can do box jumps on a concrete barrier, or run intervals in a parking lot." Constantly traveling also forced him to become a runner. "You can run anywhere in the world--and I have, on all seven continents."

Make "less bad" food decisions. Travel tends to favor quick junk food or heavy luxury food. Evans allows himself one splurge meal per week, and otherwise steers clear of sweets and takes the bread basket off the table.

"When you don't have a choice about what you're eating, then it comes down to making bad options less bad," he says. "For example, get the fish, skip the chips, and pull off the breading." For more eating out tips, sign up for the Eat This, Not That! newsletter to learn how to make healthy swaps at hundreds of restaurants.

Ironman athlete and marketing professional Peter Shankman travels 250,000 miles per year. He answers the majority of his emails on a plane and eats at home a tenth of the time he outs out, usually in another city or country.

Don't be shy. "Bellhops, receptionists, and shuttle-bus drivers usually know the best jogging routes in a new city, as do flight attendants," says Shankman. "Ask them. You might even wind up with a new running partner."

Drink, drink, drink. Flying, changing time zones, switching weather patterns, and sitting in airports or hotels are dehydrating. The more water you drink, the easier the trip is, he says.

Pack your own snacks. Airline food is filled with fats and oils. Shankman packs TSA-approved baggies of almonds, beef jerky, and other healthy foods that don't take up too much room. (Save money and Make Your Own Healthy Beef Jerky.)