ATPL Human Factors Practice Test

Jet lag typically worsens for travelers when flying east due to the nature of the body's circadian rhythms and the way time zones adjust. When someone travels east, they are effectively shortening the day and advancing their internal clock, which can disrupt normal sleep-wake patterns. Our natural circadian rhythm is roughly aligned with a 24-hour cycle, and when we fly east, we have to adjust forward in time, often resulting in a significant mismatch between our internal clock and the local time at the destination. This creates more significant challenges for recovery in terms of sleep, alertness, and overall adaptation to the new time zone. In contrast, when flying west, travelers experience a lengthening of the day, which is typically easier for the body's internal clock to adjust to, leading to less severe symptoms of jet lag. Other directions, such as north or south, do not usually involve crossing multiple time zones as east and west travel do, thus having less impact on circadian rhythms in terms of jet lag severity.