Herriott Sports Performance

From the desk of Dr. Aaron Levin M.D., HSP health consultant and shop team rider:

I just got scooped by the New York Times. (Those pointy-headed east-coast liberal-elitist, blog scooping bastards!) I swear to God, after cross natz I read a twitter post from Jonathan Page, cyclocross superstar. After notching a 3rd place at Nationals, he wrote “It is official. I do not travel well.” Page flew from Europe to Oregon a couple of days before the race, and while 3rd is nothing to sneeze at, I’m guessing the former World silver medalist might have been wearing stars and stripes if the Atlantic Ocean wasn’t so big. That got me thinking about the ways in which travel in general, and jet lag in particular can screw up athletic performance. I did my research, was about to submit this blog for your reading pleasure, and Boom! page B1 (contd. B10) of the January 7 NY Times had two articles on drugs for jet lag. I sulked for a while, but I’m over that now. Besides, my article was better, so here goes.

Travel, especially lengthy air travel can detract from an athlete’s performance in a number of ways. Some of these are obvious. For example, travel days often are enforced “rest days” from training, but they are anything but restful. Walking long distances in airports, lugging heavy bags around, sitting scrunched in a seat while your circulation is impaired are not conducive to muscle recovery. Compression garments like Skinz or 2XU can help and should be part of any athlete’s travel wardrobe. Food options during travel can also be suboptimal. Then there is the dehydration factor. Airplane air usually has a humidity level of about 10 or 20%, much lower than usual indoor humidity of 30 to 65%. Dry air can make you more susceptible to catching a cold, and dehydration itself can lead to fatigue. One rule of thumb is to drink eight ounces of water for every hour in the air. (Unlike during training, when you need to replace lost water as well as electrolytes, in a plane’s dry environment, water is all you are losing.)

A more subtle physiological effect of airplane travel has to do with altitude. Commercial planes routinely fly between 30,000 and 40,000 feet above sea level, and cabins are pressurized to make those altitudes survivable. The cabins are not, however, pressurized to match sea level. Instead, airplane cabin air is typically maintained between approximately 5,000 and 9,000 feet above sea level. At 5,000 feet, there is 17% less oxygen in the air than at sea level. At 9,000 feet, that drops to less than 25%. Those oxygen levels are not enough to cause altitude sickness, but definitely have consequences relating to recovery.

So it’s no surprise if after a big day of travel you feel worn out. The double whammy occurs when, like J. Page, you cross a bunch of time zones and mess up your circadian rhythms. Circadian rhythms are variations in physiologic characteristics that recur every 24 hours. Hormone levels within the body rise and fall over the course of each day in a predictable fashion. A number of scientific experiments have looked at peak physiologic performance and circadian rhythms. They have found that flexibility, muscle strength, and short term power output vary as a group throughout the day, but peak in the early evening. Other studies have shown that the steroid hormone cortisol, which the body produces to counteract stress, plummets late at night. Crossing multiple time zones, in addition to simply screwing up your sleep schedule, also screws up your body’s hormone schedule. So instead of racing when your body is primed, you might be trying to go hard when your body’s stress response system is literally asleep. In one Australian study, athletes who traveled to Canada had morning cortisol levels 67% lower than athletes who did not travel.

It takes a while for your body to adjust to a new time zone, and not surprisingly, athletic performance is diminished while your body is doing the adjusting. A German study measured perfomance and hormone levels in athletes who traveled either 6 time zones westward, or 8 time zones eastward. They found that jet lag symptoms, including decreased cortisol levels, body temperature, and physiologic performance, lasted for 5-6 days for westbound travel and 7 days for eastbound travel. Training performance was worst in the first four days after westbound travel.

How can one avoid the jet lag blues? There are few options and none is perfect. One strategy involves beginning to adjust your sleep schedule before you travel. This involves waking up early (or going to sleep late) depending on which direction you are traveling, and exposing yourself to bright light from the sun or a light box at your targeted wakeup time. Light and dark cycles are one of the main determinants of circadian rhythms. Melatonin has also been used to help with jet lag symptoms. It is a naturally occurring hormone that is released mostly at night in the dark. Taking melatonin at bedtime can improve sleep in jet-lagged individuals. Whether it can help make up for the performance deficits associated with jet lag is unknown. Stimulants, such as caffeine can make one feel more awake, but again, a cup of coffee probably isn’t enough to overcome the hormonal effect of trying to race in the middle of the night. There are other stimulants, such as Provigil and Nuvigil which are now being marketed for jet lag symptoms. Their stimulant effect, however, has placed them on the banned substance list, and over the past several years a number of athletes have been busted for Provigil use.

Bottom line, then, is that travel can have huge negative influences on performance capability. Especially when travelling across multiple time zones, athletes need to recognize that it probably will take 5 or more days of adjustment until they can perform at their best. (It also never hurts to have a Sherpa to carry your bike everywhere.) Looking forward to seeing how an un-jetlagged Page does at Worlds…