Fighting Fatigue

| December 12, 2008

With the right planning and practices you can work around being too tired to work.

Harvey Runyan was in cruise control, doing 70 mph, when he fell asleep Oct. 16. He rear-ended a truck pulling onto the highway and totaled his rig. “I had a full eight hours the night before,” Runyan says. “I had no warning I was going to fall asleep. I can usually tell. Not this time.”

Runyan’s story is not uncommon. Long-haul trucks are involved in two-thirds of fatigue-related crashes, according to federal statistics. Nor is it unusual that Runyan had no training in recognizing the onset of fatigue or how to deal with it.

You can minimize the negative impact of fatigue by knowing how to anticipate its onset, understanding your sleep needs and patterns, and managing your time accordingly. Eating well and exercising also help manage fatigue and keep you healthier in the long run.

Experts say people are not as smart as they think they are about knowing when fatigue begins to impair their performance. It is even possible to fall asleep with your eyes open. “A person can feel wide awake but suffer performance degradation,” says Col. Greg Belenky, director of the Neuropsychiatry Division at Walter Reed Army Institute of Research.

So by the time you’re aware of getting tired – realizing that you’re yawning too much, or that your driving reflexes are slowed – you’re at risk. “When drivers experience any effort to stay awake – and must utilize methods to stay awake – driving ability is markedly worse,” says Jim Horne, a psychophysiology professor at Loughborough University in Leicester, UK.

Learning to recognize the onset of fatigue will help prevent a dangerous micro sleep, which lasts two or three seconds or longer. This advanced stage of fatigue, which can happen without warning, means the time to stop for rest has long passed.

Some 60 percent to 65 percent of drivers are sleep deprived most of the time, says Stuart Lowenthal, chief operating officer of HealthScreenings. “Drivers who routinely get less than six hours of sleep per night and who do not have sleep disorders will show signs of impairment,” he says.

Many drivers focus simply on getting the job done and put little thought or effort into managing their fatigue. Lance Gates, an ex-owner-operator who ran the I-95 corridor for many years, says, “My idea of fatigue management was to get to Florida from The City in 17 hours straight so I could get a good night’s sleep when I got there.”

Things such as a strong work ethic or arbitrary goals, however, should not interfere with a driver’s responsibility to operate safely. And common tactics to stave off fatigue work only to a point.

Drinking coffee or playing the radio loudly may be minimally effective for short periods – enough time to get you to a rest area, for example – but reliance on any kind of stimulant will eventually backfire because it does not restore your mind to its regular alertness levels. Only sleep can do that. Finding out exactly what your sleep needs are and making sure those needs are met is the initial step in successful fatigue management.

You instinctively know how much sleep you need. Getting it at night optimizes those resting hours because of the body’s circadian (24-hour) rhythms. After the sun goes down, the body automatically lowers its temperature. Also at night, digestion slows and your body releases melatonin, a hormone that triggers sleep, experts say. When you drive beyond your optimal bedtime, this cycle is disrupted and fatigue is much more likely. Even daylight driving between 1 p.m. and 4 p.m. requires extra watchfulness because a circadian trough, or dip in alertness, occurs then. The circadian cycle is so strong that even a completely rested driver can experience some afternoon fatigue.

Dean Croke, a sleep expert and consultant to the insurance industry, says you can pinpoint your daily afternoon energy trough. “First determine your sleep mid-point, which is the halfway mark during a normal night’s sleep,” he says. “Let’s say you fall asleep at 10 p.m. and wake at 6 a.m. In this case, the mid-point would be 2 a.m. Finally, add 12 hours to determine your afternoon trough, which in this case would be 2 p.m.”

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