Raffi Manoukian spends three weeks out of every month on the road for work. And while he loves the challenge of his job, the schedule has taken its toll: The 37-year-old national sales manager for a Canadian gas- and oil-services company has gained 40 pounds over the past four years.

'I'll grab a salad with every intention of just eating the salad on the plane,' he says. But first-class upgrades come with all sorts of high-calorie goodies. 'I have a problem saying 'no' to chocolate cake,' says Mr. Manoukian, who often flies in and out of New York's La Guardia Airport.

Being a road warrior may be good for your career, but can be bad for your health. Too many restaurant meals, lack of sleep, inadequate exercise and the stress of the hectic schedule can harm the body beyond just putting on pounds, a review of multiple studies on road warriors has found.

A study by the Mailman School of Public Health at Columbia University in April found that people who traveled most frequently for work were more prone to obesity than their counterparts who traveled more moderately.

Based on the medical records of more than 13,000 workers, the odds of being obese were 92% higher for people traveling more than 21 days a month and 18% higher for people traveling between 14 and 20 days a month than their counterparts who travel between one and six days. Nontravelers were 33% more likely to be obese than light travelers, which could be explained by the fact that people in the nontravelers category include employees unfit or too ill for travel, says Andrew G. Rundle, one of the authors of the report, which was published in the Journal of Occupational and Environmental Medicine.

With obesity comes a host of other health risks, such as heart disease, Type 2 diabetes and certain cancers.

Extensive travelers also had higher diastolic blood pressure and lower high-density lipoprotein cholesterol (the 'good cholesterol') than people who traveled less frequently, the study found.

Other research finds that business travelers are more prone to other health disorders. A 1999 study of the global staff of Washington D.C.-based World Bank Group, for example, found that nearly 75% of respondents indicated high or very high stress due to business travel.

Any job comes with its share of stress, but the constantstrain of feeling rushed, overwhelmed and under pressure can affect the whole body. Headaches, mood swings and muscle tightness are common symptoms of overload. Excessive stress can also interrupt how the body functions, causing gastro-intestinal problems, an irregular heartbeat and sleep issues.

Indeed, a survey conducted for Westin Hotels & Resorts of 505 business travelers found that 55% of frequent business travelers experienced sleep deprivation, and 22% experienced sleep disruption or insomnia. Road warriors who frequently cross time zones, schedule early-morning flights and entertain late in the evening are all likely to find themselves tossing and turning.

Exercise also suffers. At home, Mr. Manoukian exercises every day. But when traveling, he packs light to avoid checking luggage -- and workout gear doesn't make the cut.

Some hotels are catering to business travelers who don't have the suitcase space for workout gear. Boutique hotel chain Kimpton Hotels & Restaurants offers free in-room yoga, Pilates and workout videos on its hotel room televisions. Guests can also request a workout basket with a yoga mat, resistance straps and other gear for use in their rooms.

'They don't have to pack clothes. They can do it in their underwear,' says Niki Leondakis, president and chief operating officer of Kimpton. The hotel created the program after fielding complaints from guests who wanted to exercise but not lug around exercise gear, she says.

Westin is rolling out a program at all of its hotels in which guests can borrow New Balance sneakers and workout gear free of charge. (Each pair comes with a disposable insole to take the ick out of re-using shoes.) Guests can also download and print running maps for different properties on the hotel's website.

Some experienced business travelers have figured out how to work in a workout.

Sally Murphy, 46, a senior district sales manager for biotechnology company Amgen Inc., always packs running shoes when traveling. She sometimes brings along resistance bands, a yoga mat and hand-held weights, she says.

Ms. Murphy, who lives in Noblesville, Ind., travels about two days a week for work, spending up to six hours in the car at a time. To avoid fast-food pit stops, she packs fruit, nuts, water and other healthy snacks in the car. 'I'm not perfect, sometimes I'll get a bag of Cheetos,' she adds.

Even the unhealthiest road warriors can be reformed. Kent Vandenberg, regional sales director for semiconductor company Entropic Communications Inc., has been a business traveler for decades and currently travels three days a week. In the past, he often scarfed down burgers and fries and sipped martinis with co-workers and clients several nights a week. Now, he often excuses himself from drinking events for yoga.

When Mr. Vandenberg turned 50, he began thinking more seriously about his health, he says. Today when he's on the road, the 56-year-old from New Hope, Pa., has a rotation of yoga studios he visits when in cities like Fort Lauderdale, Fla., San Diego, Boston and New Orleans.

At January's Consumer Electronics Show in Las Vegas, Mr. Vandenberg was the butt of jokes. 'It's supposed to be the blowout party of the century, and I'm like 'Well, I'm going to go to yoga now,' ' he says.