India Gate provided a landmark for the author, who went for an early-morning run shortly after arriving in New Delhi. (MARAL DEGHATI/AGENCE FRANCE-PRESSE VIA GETTY IMAGES)

I had been told not to run in New Delhi. The air was bad. Run in the gym, friends suggested. Just don’t go outside. I had been given similar advice in Beijing, Tehran, Baghdad, Moscow, even New York — sometimes for the air quality, sometimes because of street crime, once because of a pack of stray dogs by the Tigris River.

But I ran in New Delhi, and I ran in the other places, too. When I travel, it’s my antidote to jet lag, one that after 30 years of crisscrossing the globe I can testify really works. On the first morning in a new place, I lace up my running shoes, I find a running route, and I set out. While my traveling partners often struggle to adjust to the time zone in far-flung spots, I have little problem. By the second day on a trip, my inner clock almost always seems just right.

And there’s a hidden plus: An early-morning run means that I know my surroundings before anyone else in my party has awakened from that first night’s sleep.

Over the years, I have developed routines to cope with the rigors of crossing multiple time zones without losing the ability to function the morning after landing.

One is getting sleep on the plane. (It’s more important than watching that second movie.) A second is not drinking alcohol during a flight — a lesson learned only in recent years; it’s the best way to avoid feeling lousy when you land. A third is to go to bed in your destination at a normal bedtime.

But the fourth is the most important: Run the next morning.

Why is this so key? Lots of studies have made clear the important health benefits of regular exercise. But research also suggests that exercise helps with time-change adjustments and may speed up the return to normal circadian rhythms, or the internal body clock.

A 1987 study found that hamsters that ran on an exercise wheel adjusted to a new lab-created time zone in a day and a half, on average, while those that did no exercise took more than eight days to adjust.

Other studies on animals have suggested when might be the best time for exercise to reduce the effects of jet lag. For me, the best time is morning in whatever zone I find myself.

So last month, after getting off a plane and checking in to my New Delhi hotel around midnight, I read some e-mail, laid out my running clothes, set my alarm for 6 a.m. and turned out the light a little after 1 a.m.

At 6 a.m., I willed myself out of bed, dressed and found by the door a cardboard running map made especially for the hotel. It had a string attached, and, despite knowing that this would brand me as a tourist, I put it around my neck and slipped it under my shirt. (Only a month before, I had gotten lost in Moscow on a run to Red Square, and I was feeling uneasy about losing my way.)

I set out on a wide boulevard empty of cars. I kept on the map’s route for two blocks, and then, to my right, I saw a monument I recognized: India Gate.

In the early-morning light, I turned up its long gravel pathway and joined a few others: a man running backward; a few men doing tai chi-like movements on the grass; and groups of men wearing identical windbreakers, pants and caps walking at a fast pace. I wondered about those groups — were they cricket players or old friends since childhood or members of some club, and what were they talking about? — as I ran up and down the pathway, to the parliament building and back to India Gate, and then to my hotel.

I had seen the sun rise, I didn’t get lost, my mind was active and I didn’t feel tired. I had traveled more than nine time zones from Washington, but after a 45-minute run, my internal body clock told me it was morning: I felt refreshed and ready for breakfast.

I also treasured two other things from the run: the feeling of calmness afterward, and the sense of discovery during.

Every run, it seems, including those when I’m not traveling, brings some discovery.

Just a couple of weeks ago, while staying at a bed-and-breakfast in Matlacha, Fla., on the Gulf Coast, I ran along a causeway and watched ospreys swoop over the water, snare fish in their talons, then bring the catch to their nests on platforms atop telephone poles. Near two nests, I stopped to watch the adult osprey tear apart the fish and feed the pieces to their chicks.

When I arrived back at the B&B, I walked out to the dock to stretch. In the distance, I saw swirls of water. The swirls came closer and closer. I looked down into the clear, calm water and saw two huge gray masses — manatees — glide by. I followed them for an instant, and they were gone.

I always feel fortunate after a run. I see little treasures. I get to know the lay of the land. Perhaps best of all, I feel ready for the day — whatever time zone I’m in.

Donnelly, a former writer for the Boston Globe, is communications adviser to the president of the World Bank Group. His running blog is at john-donnelly.blogspot.com.