Air travel: considerations for runners.

If you're planning to cross a few time zones you may want to bear in mind some caveats for the runner. Airplanes obviously enable us to go places our schedules would never permit if we had to stay on the globe to get there. But the implications for the runner can be significant, especially if you're planning to compete.

Jet Lag 

Crossing time zones causes jet lag (known as transient desynchronization of the circadian rhythm to medical experts). To anyone who's suffered the symptoms it's wrecked sleep, irritability, fatigue, disorientation, confused appetites, and general misery until your body catches up with your location on the globe. And that can take a few days at best. Circadian rhythms affect daily fluctuations in heart rates, blood pressure, cardiac output and blood flow, and gastrointestinal and urinary function, as well as alertness and mental performance. To approximate how these fluctuations might affect athletic performance you can ask yourself whether you would want to run a race at say two or three o'clock in the morning. It probably wouldn't be your best effort. Here are some tips that might help you shorten jet lag and optimize your performance (or just have a better time when you get there).

* Preadaptation: In theory, you can offset the potential difference in your body clock by changing bedtime before you leave. If you live in Los Angeles and you're planning to run in the Boston Marathon, you might want to get up earlier and go to bed earlier during the week or so before you leave. Then when you arrive, you need to avoid doing things like napping or sleeping late, which would keep your rhythm on your home clock.

* Food: A high-carbohydrate, low-protein meal, (which is probably what you would choose to eat in preparation for a race) helps the brain's uptake of tryptophan and serotonin and can make you drowsy and aid sleep. A high-protein meal, on the other hand enhances the production of adrenaline and can increase arousal. Caffeine, of course, helps you stay awake when your body is saying it's bedtime. Research hasn't determined that diet changes can cure jet lag, but it hasn't refuted the theories either.

* Light therapy: There has been some research to support the use of bright lights for three hours to advance the circadian rhythms of individuals traveling across several time zones. Most airline recommendations include exposing yourself to as much of the local daylight as you can when you arrive. If nothing else, that at least helps keep you awake when you should be awake.

* Melatonin: Research is not confirming the use of melatonin to cure jet lag but studies do confirm that mela tonin can help consolidate your sleep pattern. In other words, it can help you get that night of sleep you so need when your body is completely confused about whether or not it is bedtime.

* Sleeping Pills: The American Running Association's Editorial Board Member Mel Williams, Ph.D.-- ergogenics expert and masters marathon runner-suggests getting a prescription for sleeping pills from your doctor so that you can sleep on the plane and during your first night in the new time zone. Being able to sleep that first night can help shorten the adjustment period.

(British Journal of Sports Medicine, 1998, Vol. 32, No. 2, pp. 101-106, Journal of Clinical Endocrinology and Metabolism, 2000, Vol. 85, No. 10, pp. 3618-3622;

Dermatological Surgery, 1996, Vol. 22, No. 7, pp. 637-641; Sports Medicine, 1999, Vol. 28, No. 3, pp. 197-207; Sports Medicine Digest, 2000, Vol. 22, No. 12, pp. 140)

RELATED ARTICLE: Economy CLASS SYNDROME 

Deep vein thrombosis--blood clots, usually in the deep veins of the legs--can be the result of sitting in cramped airplane seats for long flights. You know how hard it is to even shift around in your coach seat, and long hours of immobilization can cause circulation problems. Muscular contractions are part of what your body needs to get the blood in your legs back to your heart and the longer you sit in one position the higher the risk of clots. When part of a clot dislodges and travels to your lungs, that is called a pulmonary embolism and it is a serious, life-threatening medical emergency. Being of northern European descent can increase your risk, as do oral contraceptives, cigarette smoking, pregnancy, and obesity. Here are tips from American Running Association Editorial Board Member, Randy Eichner, M.D., to help reduce your risk of clotting.

* Move around--Try to get an aisle or a bulkhead seat so that you have more space. But whether or not you are that lucky, move around as much as possible. Fidget, squirm, walk the aisles, stand beside your seat and do three sets of 10 toe lifts. And don't sit with your legs crossed, which can cut off circulation even further.

* Drink--But make it water. Caffeine and alcohol will not have the diluting effect you need. Airplanes are notorious dehydrators and that can thicken your blood, making it more clot-prone.

* Eat low fat--A fatty meal can increase your risk of clotting.

* Take an aspirin? Maybe. Certain airline authorities recommend one baby aspirin before a long flight but, while it is likely to decrease your risk of a clot, there are risks associated with blood-thinning. Discuss this with your doctor before you fly.