When he got to Yorkshire, England, on a recent trip, Robert Rosenberg began one of his standard routines: He laced up his sneakers and took an afternoon jog.
Rosenberg was, in reality, doing more than getting fresh air and exercise; he was adjusting his body to the local time zone, which was eight hours ahead of his home in Arizona.
Rosenberg, a doctor of sleep medicine who runs the Sleep Disorders Center of Prescott Valley, in Arizona, USA, was beating jet lag with exercise and exposure to afternoon sunlight. Both are elemental to overcoming jet lag, he said.
Both exercise and exposure to the afternoon sunlight are are elemental to overcoming jet lag.
"I know it helped me get acclimated, getting exercise and getting out there in the light, rather than sitting in a hotel room," Rosenberg said.
Although a few lucky travellers might be immune to jet lag, most of us have suffered through that wobbly sensation of being half a world from home in a deep, disorienting exhaustion. It often is impossible to avoid because of the chasm between our circadian rhythms - the biological process that juggles consciousness and sleep - and a new surrounding where sunrise and sunset don't mesh with what our body expects.
The challenge is particularly acute when travelling across at least three time zones, Rosenberg said; it takes about a day to adjust for every time zone crossed heading east and half the time when travelling west.
The problem for a person on a regular day/night schedule, Rosenberg said, is that the brain's pineal gland is accustomed to producing the melatonin we need to sleep about 9 or 10 pm - but, when whisked across the Atlantic Ocean, that's suddenly 4 or 5 am in, say, Prague.
Worse, we continue to get that melatonin well into Prague's daytime. The fallout can be quite unpleasant: insomnia, fatigue, an inability to concentrate and even constipation and indigestion.
"It takes brain several days or more to change its inherent cycle and phase in with a new night and day in the new destination," Rosenberg said. "Trying to budge the circadian clock can be hard to do."
But it can be done. Here are Rosenberg's suggestions:
For three nights before travelling east, go to sleep an hour earlier than usual and wake up an hour earlier. When travelling west, sleep an hour later and rise and hour later.
When freshly landed somewhere to the east, don't expose yourself to light until the afternoon. Why?
"The brain is still back home; if you're in Paris and you get up at 8 am and expose yourself to bright light, it is still nighttime to your brain. You want to do everything you can to help your brain adjust to the new time, so expose yourself to sunlight at 4 pm, when it's 8 am back home. Just wear sunglasses until then, and then take them off. It's about easing yourself in."
Rosenberg suggests taking 0.5 milligrams of melatonin for the first two or three nights in your destination. "It's very safe, and it's a great way to get through jet lag," he said. A sleeping pill, he said, should always be a last resort. "I try to use natural methods first," he said.
DON'T GIVE IN (TOO MUCH)
If you have to nap on the day you arrive in a far-off place, keep it to no more than two hours.
Try to arrive in your destination in the afternoon, which will allow you to go to sleep at a "normal" bedtime.
Business trip? Go a couple days early to adjust. "You don't want that meeting to be on the first day you're there," Rosenberg said.
When you get to your destination, eat foods high in tryptophan - dairy, red meat, fish and peanuts - which help stimulate melatonin.
SLEEP ON THE PLANE
Obvious, but several hours of sleep en route can make a huge difference toward getting on a regular sleep schedule.
It helps you fall asleep more easily.
THE LITTLE THINGS
Small advantages help: Turn off electronics 90 minutes before bedtime (melatonin production is suppressed by the bright light from a mobile phone or tablet); don't drink too much alcohol (which interferes with sleep in a variety of ways) or caffeine after about noon.