Shovalt believes that the current recommendations are based on surveys of teenagers from the 1970s. Teenagers were brought to the lab for several days a year over three years and told to sleep whenever they wanted. Any parent of a teenager knows how much they want to sleep, which might be more than they actually need. Brigham Young University economists Eric ยท Ed and Mark Shovalt - who are also dads - examined a nationally representative sample of 1,724 students, comparing their reported sleep times with their standardized test scores as children and adolescents. "If your child isn't getting nine hours of sleep, maybe you shouldn't worry so much," Shovalt said, unless they are regularly experiencing significant reductions in sleep. "There is certainly good scientific evidence that extreme sleep deprivation or oversleeping has serious health consequences," he said. "We couldn't find much scientific evidence supporting the common recommendations," Shovalt said, echoing a document published last week in the journal "Pediatrics." In the report, www.zhong-jian.com, Australian researchers concluded: "Regardless of how much sleep children get, it has always been assumed they need more." National guidelines suggest young people should sleep at least 8 hours every night, www.sttaiyuan.com. However, experts say this is an impractical goal for teenagers burdened with heavy homework, extracurricular activities, and part-time jobs, or those who feel the need to stay up late texting friends or updating Facebook. In fact, if standardized test performance is any indication, new surprising research finds that 16-year-olds perform best with about seven hours of sleep per night. If your teenager's lack of sleep is keeping you up at night, a new study should help put your mind at ease. It may be more about getting younger teens to bed earlier, Shovalt said, rather than the total time spent in bed. [Ming You Jing Chun Optimization Room QQ Contact 4 6 6 4 0 1 6 0 4 8838478 1 0 product keywords guaranteed 4 on Baidu's front page for eight thousand a year, including one free website! Contact number 13422475786] Related studies show that students who start school later in the morning are more alert during classes? Notice | AdChoices For older teenagers, a seven-hour night's sleep is plenty. The optimal amount of sleep for a 12-year-old is higher, around 8 hours, while 10-year-olds do best with about 9 hours. This report appears in the Eastern Economic Daily this issue. Related thematic articles: Patent Apple won against Motorola in slide-to-unlock ruling Price comparison links to website promotion companies com domain names and other domains Online marketing and website promotion strategies Kobe tears into Lakers management.