I’ve been traveling, both for business and for recreation, my entire adult life. I also used to believe that drinking water was the best prevention/cure and, aside from that, I should allow a day’s recovery for every time zone crossed. Since then I’ve learned a lot, both from research and my own personal experience.
What is Jet Lag?
Jet lag occurs when our circadian rhythms no longer align with the environment. Circadian rhythms are “physical, mental and behavioral changes that follow a roughly 24-hour cycle, responding primarily to light and darkness in an organism’s environment (NIH definition).” Since light is the main cue influencing circadian rhythms (it turns on or off genes that control our internal clocks), we experience physical and mental symptoms when we cross multiple times zones quickly. Example: flying from New York City to Western Europe. If we wake up at 7:00 am European Time and see early morning light, but our circadian rhythms are still functioning like it’s 1:00 am and completely dark outside, we are out of sync with the natural environment. We feel tired, depressed, and have trouble thinking clearly. These are just the short-term effects. The long-term effects of constant jet travel are just now being discovered. They include cognitive defects, GI disturbances, an increased risk of cancer, and even heart disease. Some research shows jet lag eventually causes your brain to shrink. The bad news is that the effects of jet lag get worse with age, particularly after the age of 50.
There’s more: jet lag is also characterized by lack of oxygen in the blood, and dehydration. When flying, people experience a 5% to 20% drop in the amount of oxygen in their blood. This depends on the person, the plane and the length of the flight. A long-haul flight on anything but a Dreamliner (they can be pressurized more than other planes because their fuselages are made of advanced composite materials) typically results in blood oxygen levels dropping close to the 20% number. We get dehydrated when we fly because average cabin humidity is around 20%- most people feel comfortable when ambient humidity is between 40%-70%.
What does this all mean? First, jet lag is largely preventable. Clinical research conducted at NASA has demonstrated that we can adjust our body clocks six hours in one day, and up to twelve time zones in two days. Second, much can be done to relieve the symptoms of jet lag.
How do we prevent jet lag and relieve its symptoms?
Aside from staying well hydrated (lots of water, no alcohol, limited caffeine), there are three tools for managing jet lag: (1) light exposure, (2) melatonin and (3) exercise.
1. Light exposure: Since light cues our circadian rhythms, seeking and avoiding light at the proper times can reduce jet lag. Bright light exposure can cause a phase shift — an advance or delay in circadian rhythms. Light in the early morning makes you wake up earlier- called a phase advance; light around bed time makes you wake up later- called a phase delay. There are calculations you can use to determine the proper way to phase shift based upon where you’re traveling and when. My new app for travelers, The Flying Carpet, will include a tool to help users do this.
2. Melatonin: Melatonin is a hormone created by your pineal gland, a small gland in the brain. It helps control circadian rhythms. Light affects how much melatonin your body produces. If you don’t want to phase shift before you leave, you can also take synthetic melatonin to increase your body’s melatonin levels. Melatonin is sold over the counter in the US, although it has not been regulated by the FDA. In much of Europe, it requires a doctor’s prescription. In the UAE it is illegal- so be careful flying to Dubai. Moreover, it has side effects and is ineffective in the long run. An alternative is to increase your brain’s melatonin production naturally through certain types of meditation. It has been demonstrated that a special kind of guided meditation called yoga nidra (nidra means sleep in Sanskrit), increases the pineal gland’s production of melatonin. My new app for travelers, The Flying Carpet, will include nidra exercises you can do on the plane, and after arriving at your destination, specifically designed to combat jet lag.
3. Exercise: There are two ways exercise helps. Recent studies have found that scheduled exercise alters the molecular clock in tissues like the muscles and lungs. Interestingly, exercise has no effect on the brain’s central clock. Meaning exercise is like the water- it’s a tool to help you feel better, but you still need to tackle the cause of the problem with calculated light exposure and/or melatonin. The best time to exercise is after your flight, on the same day. It is also helpful to do exercises on the plane.
Yoga and Jet Lag Prevention
Yoga is the ideal exercise for jet lag prevention- some airlines even feature yoga stretches in their in-flight magazines and programming. Yoga is a broad discipline, not just confined to physical stretching. Here are the three main types of yoga, and how they can help manage jet lag:
Yoga Nidra: stimulates your brain’s natural melatonin production. Can be done on the plane, or before you go to bed. Nidra is best done with your eyes closed in a quiet place. Promotes sleep and helps you feel more relaxed.
Pranayama (breathing exercises): Helps re-oxygenate your blood, and can be done almost anywhere. Breathing exercises also help manage anxiety- perfect for nervous flyers.
Physical stretches: Gives your body the benefits of regular exercise. Additionally, certain stretches can relieve symptoms of bloating that result from pressure changes, and increase circulation in the legs.