It's a common traveler's dilemma: to avoid jet lag after a long-haul flight, you should really sleep on the plane. That way, you can wake up refreshed and already be on local time. The problem: you can't sleep on planes. If you've ever arrived at an airport feeling groggy like Bill Murray's character in the...

Sometimes we feel like we don’t need as much sleep when we’re traveling, because the excitement and energy we get from our new surroundings and adventures is enough to keep us going. I’ve heard travelers romantically recount exhausting stories about traveling and, due to situation, not sleeping for days at a time. I’ve even told...