Teens who sleep at least eight hours each night have a 68% lower risk of sports injury compared to those who regularly sleep less, researchers reported at the American Academy of Pediatrics (AAP) National Conference and Exhibition in New Orleans, yesterday.

Several studies recently have demonstrated a range of benefits for children who either get more sleep, or manage to slumber during the recommended hours each day. Researchers from Canada reported in Pediatrics last week that children who sleep an extra 27 minutes each weekday night have considerable improvements in behavior at school.

The abstract was called "Lack of Sleep is Associated with Increased Risk of Injury in Adolescent Athletes".

The researchers asked school athletes - 160 students, 54 males and 58 females, mean age 15 years - from middle and high school, grades 7 to 12, who were part of the Harvard-Westlake School in Studio City, California, to complete a questionnaire which requested details of their sports, how much time they spent in each sport both at school and outside, did they have private coaching, were they involved in any strength training, what their sleeping patterns were, and how much they enjoyed their sport.

The questionnaires were completed by 112 of them. The researchers then analyzed them, specifically looking at sleeping patterns, and checked the school records for sports injuries.

They found that the more sleep the pupils got, the lower their risk of injury seemed to be.

The higher graders were much more likely to be involved in a sports injury, 2.3 times more likely for each additional school grade, they found. The following did not significantly increase risk of injury: how many hours they practiced each week, how many sports they did, whether or not they were involved in strength training, whether the sport was fun, and whether a private coaching was done.

Senior author, Matthew Milewski, MD., said:

"While other studies have shown that lack of sleep can affect cognitive skills and fine motor skills, nobody has really looked at this subject in terms of the adolescent athletic population. When we started this study, we thought the amount of sports played, year-round play, and increased specialization in sports would be much more important for injury risk. (Instead) what we found is that the two most important facts were hours of sleep and grade in school."

Milewski believes the higher risk among the older students may be due to two factors, among others:
  • Older athletes are stronger, faster and bigger.
  • Older students have a cumulative risk for injury after having played for a few years.
In another study, researchers from Massachusetts General Hospital and Boston Children's Hospital explained in Journal of Clinical Endocrinology and Metabolism (JCEM) that deep sleep is crucial in the development of puberty. During puberty, hormones change considerably, and the teenager is likely to become more clumsy at times.

Written by Christian Nordqvist