Circadian rhythm disruption occurs when the rhythm set by one’s biological clock is misaligned with the solar day and night cycle of the environment. One of the most acute disruptions to circadian rhythm is rapid travel across time zones – a phenomenon known as jet lag. Jet lag not only impacts individual travelers but can also affect a company’s bottom line. In fact, a recent study found that mistakes made by jet lagged staff members cost UK businesses more than EUR 240 million (USD 311 million) during 2016.
To minimize the symptoms of jet lag, travelers need to recognize that their internal clock and circadian rhythm are dependent on environmental cues, such as light. Travelers who are unaware of this often use ineffective and even harmful means to minimize the symptoms of jet lag, such as alcohol and excess amounts of caffeine. Even though there is no single treatment to combat jet lag or its effects, scientists have developed useful recommendations and guidelines to help minimize its symptoms. This blog post attempts to present simplified, best practice information, while acknowledging that a host of other information – which some may find confusing or complex – exists on the Internet.
General Guidelines for How to Minimize Jet Lag
The first question you should ask when considering what steps to take to minimize jet lag is this: How many days will I be traveling? This simple metric is useful to determine whether or not you should shift and adapt your biological clock to a destination’s local solar time. These guidelines are primarily based on a 2009 article published in Sleep Medicine Reviews – a peer-reviewed medical journal.
Traveling for 1-2 Days
When you plan to be in a destination for only one to two days, there really is no point in helping your circadian rhythm adapt to the destination time zone – by the time you become adapted to this time zone, you will arrive back at home. The general advice for this scenario is:
- Sleep when you can.
- Maintain alertness by using stimulants, such as caffeine.
- Schedule important meetings when you will have a higher propensity to stay awake; be aware that your circadian rhythm will be off, and therefore, your performance could be askew, as well.
Traveling for More Than 4-5 Days
Pre-flight preparation is necessary when you plan to be in a destination for more than four to five days, especially if it is critical that you be able to work immediately upon arrival. The primary goal of the guidelines presented below is to help shift your internal clock in the correct direction to help minimize the effects of jet lag.
These guidelines should be followed starting prior to departure and continuing for three to four days after arrival. It is extremely important to note that both light and melatonin (0.5 mg pre-flight and 3-5 mg post-flight) are used together in this protocol. Furthermore, all times are noted relative to departure location time, because that is the time your biological clock is synchronized to prior to the protocol.
How to minimize jet lag going west
When you travel westward, you are actually traveling back in time compared to the 24-hour rotation of the earth. Therefore, your internal clock needs to shift back in time to remain in sync with the 24-hour rotation of the earth.
- Avoid Bright Light during the Morning: Since light exposure in the early morning causes the internal clock to shift forward, avoid bright light during the departure location’s early morning.
- Seek Bright Light during the Evening: Since light exposure in the late evening shifts the internal clock back in time, seek bright light during the departure location’s late evening.
- Take Melatonin during the Early Morning: Melatonin should be taken during the departure location’s early morning (0.5 mg pre-flight and 3-5 mg post-flight).
How to minimize jet lag going east
When you travel eastward, you are actually traveling forward in time compared to the 24-hour rotation of the earth. Therefore, your internal clock needs to shift forward in time to remain in sync with the 24-hour rotation of the earth.
- Seek Bright Light during the Morning: Since light exposure early in the morning causes your internal clock to shift forward, seek bright light during the departure location’s early morning.
- Avoid Bright Light during the Evening: Since light exposure late in the evening shifts your internal clock back in time, avoid bright light during the departure location’s late evening.
- Take Melatonin during the Early Evening: Melatonin should be taken during the departure location’s very early evening (0.5 mg pre-flight and 3-5 mg post-flight).
What About Traveling for 3-5 Days?
The same strategies used for “Traveling More Than 4-5 Days” can be used for trips that last three to five daysto achieve partial adaptation to the new time zone, if you want to create a more favorable sleep schedule. However, it is important to note that even though adapting to solar time of the new destination is optimal, it may be very difficult to achieve in this situation because of the intermediate length of such trips.
A Few More Words on Melatonin and Light
Melatonin is not readily available in most countries. In the US, melatonin can be found over-the-counter. However, since melatonin is considered a nutritional supplement, it is not regulated by the FDA. According to the National Academy of Science, short-term use of melatonin at a daily dose less than or equal to 10 mg is safe in healthy adults who are not taking other dietary supplements or concurrent medications. The American College of Physicians recommends that melatonin be avoided by people who have asthma and people who plan to drive or operate heavy machinery within eight hours of taking it. All travelers should consult with their healthcare provider before using melatonin.
Strategies to avoid light include wearing protective eyewear, sleeping, and staying in a darkened room. Whenever possible, individuals attempting to avoid light should also avoid using electronic devices such as computers, smartphones, or televisions. Strategies to expose oneself to light include going outdoors during daylight, using special room lighting, or using a commercial light box. People taking photosensitizing agents, such as malaria medications and certain antibiotics, should use caution when using a commercial light box.
Jet lag is observed when a traveler arrives in a new time zone that differs widely from his or her home time zone. Because this new time zone has a different solar time, the traveler’s internal clock is not synchronized with it. Symptoms of jet lag persist until the internal clock shifts and synchronizes with the solar time in the new time zone; the ability of the internal clock to synchronize with a new solar time varies from individual to individual. Guidelines, advice, and even apps regarding the management and prevention of jet lag are readily available; however, it is easy to become overwhelmed in this sea of possibly conflicting information. The information in this blog post highlights practical, cohesive strategies that can be used to help you combat jet lag.