I've spent 27 of the last 96 hours on Amtrak. I'm disoriented and irritable, my body aches, and I'm eating and sleeping at odd hours. In short, I'm jet-lagged.

At least by definition, I can't have jet lag because my North-South trains didn't cross any time zones and wouldn't have screwed up my internal body clock. Besides, train travelers aren't supposed to get jet lag. That's why it's called jet lag. And after 30 years on the road, sometimes flying nonstop for as long as 18 hours at a time, I generally don't have issues with jet lag.

But I know jet lag when I experience it. And that may tell you all you need to know about the topic. Fifty years after the first commercial-jet flights began to inflict jet lag on travelers, the condition and its effect on our minds and bodies is still a matter of fierce medical debate, a topic of endless discussion among business travelers, and a fertile market for any huckster with a purported cure.

When I edited Frequent Flyer magazine almost 20 years ago, I counted more than 150 items touted as jet-lag cures or preventatives. There were pills, potions, diets, software programs, books, drugs, exercises, gadgets like light boxes, and watches with special faces, and even a former flight attendant who claimed feel-good visualizations and mantras were the ticket. When I googled the term "jet lag" today, I got more than 5.4 million hits. The watch and the former flight attendant are still around, by the way.

All this may sound silly, but jet lag is serious business for business travelers and the companies that send executives around the globe. Many firms are so concerned about the mind-numbing and strength-sapping effects of jet lag that they bar employees from negotiating or signing contracts for the first 24 hours after they fly.

The real-life impact of jet lag is easier to describe than its cause. Consult the Centers for Disease Control, for example, and you'll get this bit of gobbledegook: The term "jet lag" is used to describe symptoms that result from temporary de-synchronization of circadian rhythm between a traveler's internal clock and the external environment.

In plain English, we're creatures of habit and our minds and our bodies expect predictable cycles of night and day, waking and sleeping, eating and hydration. Your body's rhythms get confused when you move too rapidly between time zones and it is suddenly confronted with new periods of daylight, sleeping, and nutrition. Our bodies eventually adjust to the rhythmic changes, of course, but much more slowly than jet travel moves us. Some experts say that the recovery rate is as slow as one day for each time zone you cross.

Travelers are naturally eager to speed up the adjustment process or negate the effects of jet lag altogether. The problem? Since jet lag affects everyone differently, there is no sure cure, and no way to separate the good treatments from the bad.

In fact, purported cures and preventatives are often diametrically opposed to each other. One popular vein of jet-lag treatment is diet. Some shamans claim that eating a diet rich in carbohydrates before you depart on a long trip will help mitigate the effects of jet lag. But other diets propose a strict low-carb regime. The best-known anti-jet-lag diet, formulated decades ago at the Argonne National Laboratory, actually mixes high-protein menus with high- and low-carb meals. Whether it, or any diet, actually "works" is a matter of personal impact. Some fliers swear by it, others laugh and keep suffering.

Another popular strain of jet-lag treatment is light therapy. Some travelers fly with special lighting gear to simulate sunlight. Others swear by special eyeshades that block out light. Hotels often play both sides, outfitting their rooms with "blackout" curtains and high-tech lighting fixtures that mimic sunlight.

And then there's melatonin, a naturally occurring hormone created by the pineal gland in response to daylight and darkness information received by the retina. Available since 1993 in the United States as a dietary supplement, melatonin pills are wildly popular with a segment of jet lag-obsessed business travelers. Supporters claim melatonin naturally resets your body clock overnight.

The cornucopia of putative cures also includes herbal remedies (a recent product I received claimed to guard against "a full spectrum of jet lag symptoms"); aromatherapies (popular in the amenities kits distributed by international airlines in their premium classes); and hard drugs (a lot of travelers ingest copious amounts of the prescription sleep aid Ambien). Some travelers claim vigorous exercise is curative, and I know folks who swear by a shot of Fernet Branca, a bitter Italian herbal liqueur, or, in a pinch, a snifter of cognac.

Odd rituals abound too. Some fliers stuff brown paper in their shoes, others believe a barefoot romp on a carpeted floor helps. Still others insist on a shower or a swim upon arrival. And many claim that immediately switching to the local time at your destination when you step onto your departing flight will help your system adjust to the new time zone.

None of these "cures" are right or wrong. The right approach is the one that works for you.

What works for me? I never eat or drink alcoholic beverages on planes. I consume an immense amount of water (in-flight air is extremely low in humidity). After an eastbound flight, I always take a quick nap on arrival. (I'm weirdly energetic after westbound flights.) And years ago, a savvy frequent flier gave me a tip he said he got directly from President Lyndon Johnson: No matter where you are, live your life on your home time zone. So I never change my watch, I eat on New York time wherever I am, and, as much as possible, sleep on New York time too.

Now if I can just figure out why I have jet lag after a train ride.

The Fine Print.
Jet-lag treatments sometimes run afoul of local law. A traveler to Dubai was recently jailed for several weeks after he was arrested with a bottle of melatonin pills in his possession.

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