VOA标准英语2010年-American Teenagers Dangerously Sleep D

（单词翻译）

About 50 percent of American teenagers are not getting the sleep they need during the school year, according to a poll by the National Sleep Foundation. 

Experts say that teens are biologically programmed to go to sleep later and get up later than other age groups, which makes their body's natural rhythm incompatible¹ with early school hours. And this sleep deficit² is having negative consequences on almost all facets³ of teens' lives.

Now, an increasing number of educators are trying to reconcile the sleep needs of their teenage students with the practical realities of earlier school schedules.

Sixteen-year-old Danny is also part of a growing number of teenagers who are sleep deprived.
 

Dozing⁴ at their desks

Sixteen-year-old Danny is a typically active teenager. He plays lacrosse and football and likes listening to rock music. But Danny is also part of a growing number of teenagers who are sleep deprived.

"Getting up in the morning is pretty terrible," he says. "I'm just very out of it and tired. And then, going to school, I'm out of it. And through first and second period [classes], I can barely stay awake."

Danny is not alone. Surveys show that half of all teenagers in the country are missing an average of one to 1½ hours of sleep every school night, and that's having negative consequences on their performance - in and out of the classroom.

While some believe that a teenager's reluctance⁵ to get up in the morning is sheer laziness, sleep experts say that's not necessarily the case. Michael Breus, a clinical psychologist who specializes in sleep disorders⁶, says kids like Danny aren't just a bunch of lazy kids.

"These are children whose biological rhythms, more times than not, are off," says Breus.

Negative consequences

Teenager's biological rhythms - often referred to as their circadian rhythms - favor later bedtimes and later wake-up times.

But, with many school systems starting classes as early as seven a.m., teenagers like Danny often come to school half asleep. And that, says Breus, has consequences.

"We have long known that the more sleep deprived you are, the more cranky you are. So when your child, who really needs eight or nine hours, is only sleeping for seven hours a night, they are going to experience a form of depression that could be significant and could have some pretty major effects on their overall well-being⁷."

According to Breus, that mood-altering deficit can affect a teen's academic performance, their athletic⁸ ability and even their performance behind the wheel of a car.

"We know that drowsy⁹ driving is of utmost concern because these are kids who haven't had a tremendous amount of experience in driving to begin with." Any drowsy driver is dangerous, says Breus, but a teenager with a lack of experience can be even more dangerous.

He acknowledges that there are other factors that contribute to a teenager's sleep loss. Twenty-four-hour access to the Internet and fast-paced video games are tempting¹⁰ products in the digital age. And the proliferation of caffeinated drinks is also wreaking¹¹ havoc¹² with our children's natural body rhythms. But school, says Breus, is one area where small changes can bring about dramatic results.

"There've been multiple research studies that now show that in fact when you change the school start time, allowing children to start later in the morning, their grades go up by almost a full letter grade in their first- and second-period (classes)," he says.

 
Suzanne McGrady
Headmaster Eric Peterson of St. George's School in Newport, Rhode Island, saw positive results after changing his school start time from 8:00 to 8:30 am.
 

Later school start time equals happier, healthier teens

Dozens of school districts around the country have been looking at these studies and are considering ways to adjust their class schedules.

Eric Peterson is head of St. George's School, a private boarding school for grades 9-12 in the northeastern state of Rhode Island.

After looking at the medical research on adolescent sleep needs and observing students in his own school, Peterson consulted with Dr. Judy Owen, a renowned¹³ pediatrician and sleep expert.

Armed with what he considered to be compelling data, Peterson decided¹⁴ to change his school's start time from 8:00 am to 8:30 am on a trial basis to see if a 30-minute change would make a difference. He was surprised by the results.

"What was really astonishing was how many benefits and how significant the benefits were," he says. "In the research itself, we saw just over a 50 decrease in health-center admissions for fatigue¹⁵, or fatigue-related illness, or rest requests. We saw almost 35 percent decrease in first-period tardiness¹⁶. Students reported that they were more alert. They were less sleepy during the day."

And, according to Dr. Patricia Moss¹⁷, assistant dean for Academic Affairs at St. George's School, students weren't the only ones reporting better results in the classroom. She says virtually all the teachers almost immediately noticed much more alertness in the classroom, and there was definitely a more positive mood all around.

"Kids were happier to be there at 8:30 than they were at 8:00," she says. "So our experience across the total spectrum¹⁸ was, universally, extremely positive and surprisingly so."

Headmaster Peterson says there was another unexpected area of change when the school changed its start time.

"We saw probably a greater than 30 percent increase in student attendance at breakfast, and of the food that they were eating. We more than doubled the amount of milk, eggs, fruit and cereal. So it was quality breakfast foods that the kids were eating. So they were better fueled as well as better rested."

Ross and Peterson acknowledge that making schedule changes has been easier at a small, private boarding school than it might be for the larger U.S. public school system.  But they are hopeful that others will find a way.

"In the end," says Peterson, "schools ought to do what's the right thing for their students, first and foremost, and this element of the program is very clear - certainly for us as a school - but I think as a general example to other schools, is pretty compelling, and so I would argue that it's worth doing." 

Whether or how a school or a school district is able to do it, he says, or finds the will and skill to accomplish it, "that's the job of talented, smart school administrators," he says.

In the meantime, experts say that - as we learn more about adolescent sleep patterns and exactly why they need those nine hours of sleep - it is up to families and individual students like Danny to take personal responsibility for paying more attention to sleep as an essential element of a healthy life.