Endurance management: Maximizing the Air Force's most vital asset

Mobility Forum, Jul/Aug 2003 by O'Brien, David, Rock, T M

A healthy lifestyle is a great aid to overcoming fatigue. Regular physical exercise conditions the body to sustain performance and delay the early onset of fatigue. Physical exercise is also an excellent relief valve for normal emotional stress associated with our busy lives. Avoid exercise within several hours of sleeping so your body is winding down at bedtime. The foods we eat can play a role in endurance and fatigue as well. Foods high in protein contain the chemical tyrosine. Tyrosine increases the production of neurotransmitters in our brain that enhance energy and alertness. So eating appropriate portions of meats, nuts, peanut butter, cheeses and fish can help your performance. On the other hand, eating foods high in the amino acid tryptophan can lead to sleepiness. When tryptophan reaches the brain it makes you relax and become sleepy. Turkey contains a great deal of tryptophan, as does corn, white breads and potatoes - so avoid significant portions of these foods when vigilance and attention are required during long duty days. We all remember falling asleep after eating a wonderful Thanksgiving dinner; great on a holiday, but not on a transoceanic mission. Finally, it is important to avoid concentrated sweets and fats during long missions. Box lunches don't always help us here, as they frequently include candy bars and sugared sodas. The result of these products are soaring blood sugar highs followed by lowered blood sugar - adding further to our fatigue and decreased concentration. Fruits, vegetables, complex starches (bread, grain, rice) and protein provide a longer lasting, more sustained energy release.

The moderate use of caffeine can be used as a tool for alertness, but it can also hinder restful sleep. The body can handle about 200-250mgs of caffeine a day without too much trouble. A can of cola has about 38 mgs; a cup of drip coffee can have over 100mgs. When used for enhancing alertness, a caffeinated soda or coffee can be consumed about 30 minutes prior to a significant event, such as aerial refueling or descent/landing. Try to avoid drinking too much caffeine, as it can over stimulate the nervous system and impair quality sleep.

On the near horizon is a new tool to help aircrew and shift workers schedule sleeping periods and naps. The Fatigue Avoidance Scheduling Tool (FAST) is a computer program that processes work schedules and predicts levels of performance and recommends sleeping/nap strategies. The current test version is adequate for teaching and limited operational use. FAST can be accessed by aerospace physiologists who are assigned to your local aerospace medicine unit.

Long missions are a way of life in AMC, particularly during our efforts to support OPERATION IRAQI FREEDOM; our AMC aircrews are frequently flying 26-hour missions and back in the air again after a 12-hour rest period. This is a demanding schedule. Here is a wrap up with succinct, practical examples for aircrews and others to improve endurance during high ops tempo periods. Maximize your crew rest avoid alcohol, read or listen to quiet music to wind down prior to sleep, darken your room, turn on a fan or wear earplugs to decrease ambient noise. No-Go pills can help initiate sleep and can be used for approved mission profiles. While flying, getting up for a stretch or walk can stimulate the mind and body. Moderate use of caffeine can also temporarily combat fatigue and increase alertness. When crew conditions permit, a short nap for 20 - 60 minutes offsets acute fatigue and physically refreshes. Limit eating and drinking of concentrated sweets.