Exercise may help teens sleep longer, more efficiently
May 22, 2019
Science Daily/Penn State
Getting more exercise than normal -- or being more sedentary than usual -- for one day is enough to affect sleep later that night. Researchers found that when teenagers got more physical activity than they usually did, they got to sleep earlier, slept longer and slept better that night.
In a one-week micro-longitudinal study, the researchers found that when teenagers got more physical activity than they usually did, they got to sleep earlier, slept longer and slept better that night.
Specifically, the team found that for every extra hour of moderate-to-vigorous physical activity, the teens fell asleep 18 minutes earlier, slept 10 minutes longer and had about one percent greater sleep maintenance efficiency that night.
"Adolescence is a critical period to obtain adequate sleep, as sleep can affect cognitive and classroom performance, stress, and eating behaviors," said Lindsay Master, data scientist at Penn State. "Our research suggests that encouraging adolescents to spend more time exercising during the day may help their sleep health later that night."
In contrast, the researchers also found that being sedentary more during the day was associated with worse sleep health. When participants were sedentary for more minutes during the day, they fell asleep and woke up later but slept for a shorter amount of time overall.
Orfeu Buxton, professor of biobehavioral health at Penn State, said the findings -- published today (May 22) in Scientific Reports -- help illuminate the complex relationship between physical activity and sleep.
"You can think of these relationships between physical activity and sleep almost like a teeter totter," Buxton said. "When you're getting more steps, essentially, your sleep begins earlier, expands in duration, and is more efficient. Whereas if you're spending more time sedentary, it's like sitting on your sleep health: sleep length and quality goes down."
While previous research suggests that adolescents need eight to ten hours of sleep a night, recent estimates suggest that as many as 73 percent of adolescents are getting less than eight.
Previous research has also found that people who are generally more physically active tend to sleep longer and have better sleep quality. But the researchers said less has been known about whether day-to-day changes in physical activity and sedentary behavior affected sleep length and quality.
For this study, the researchers used data from 417 participants in the Fragile Families and Child Wellbeing study, a national cohort from 20 United States cities. When the participants were 15 years old, they wore accelerometers on their wrists and hips to measure sleep and physical activity for one week.
"One of the strengths of this study was using the devices to get precise measurements about sleep and activity instead of asking participants about their own behavior, which can sometimes be skewed," Master said. "The hip device measured activity during the day, and the wrist device measured what time the participants fell asleep and woke up, and also how efficiently they slept, which means how often they were sleeping versus tossing and turning."
In addition to finding links between how physical activity affects sleep later that night, the researchers also found connections between sleep and activity the following day. They found that when participants slept longer and woke up later, they engaged in less moderate-to-vigorous physical activity and sedentary behavior the next day.
"This finding might be related to a lack of time and opportunity the following day," Master said. "We can't know for sure, but it's possible that if you're sleeping later into the day, you won't have as much time to spend exercising or even being sedentary."
Buxton said improving health is something that can, and should, take place over time.
"Becoming our best selves means being more like our best selves more often," Buxton said. "We were able to show that the beneficial effects of exercise and sleep go together, and that health risk behaviors like sedentary time affect sleep that same night. So if we can encourage people to engage in more physical activity and better sleep health behaviors on a more regular basis, it could improve their health over time."
In the future, the researchers will continue to follow up with the participants to see how health and health risk behaviors continue to interact, and how sleep health influences thriving in early adulthood.
Russell T. Nye, graduate student at Penn State; Nicole G. Nahmod, Penn State; Soomi Lee, assistant professor at the University of South Florida; Sara Mariani, Harvard Medical School; and Lauren Hale, professor at Stony Brook University, also participated in this work.
https://www.sciencedaily.com/releases/2019/05/190522081513.htm
Insufficient sleep in children is associated with poor diet, obesity and more screen time
New study suggests a relationship between insufficient sleep and an unhealthy lifestyle
November 12, 2018
Science Daily/American Academy of Sleep Medicine
A new study conducted among more than 177,000 students suggests that insufficient sleep duration is associated with an unhealthy lifestyle profile among children and adolescents.
Results show that insufficient sleep duration was associated with unhealthy dietary habits such as skipping breakfast (adjusted odds ratio 1.30), fast-food consumption (OR 1.35) and consuming sweets regularly (OR 1.32). Insufficient sleep duration also was associated with increased screen time (OR 1.26) and being overweight/obese (OR 1.21).
"Approximately 40 percent of schoolchildren in the study slept less than recommended," said senior author Labros Sidossis, PhD, distinguished professor and chair of the Department of Kinesiology and Health at Rutgers University in New Brunswick, New Jersey. "Insufficient sleeping levels were associated with poor dietary habits, increased screen time and obesity in both genders."
The study results are published in the Oct. 15 issue of the Journal of Clinical Sleep Medicine.
The American Academy of Sleep Medicine recommends that children 6 to 12 years of age should sleep nine to 12 hours on a regular basis to promote optimal health. Teenagers 13 to 18 years of age should sleep eight to 10 hours.
Population data were derived from a school-based health survey completed in Greece by 177,091 children (51 percent male) between the ages of 8 and 17 years. Dietary habits, usual weekday and weekend sleeping hours, physical activity status, and sedentary activities were assessed through electronic questionnaires completed at school. Children who reported that they usually sleep fewer than nine hours per day, and adolescents sleeping fewer than eight hours per day, were classified as having insufficient sleep. Anthropometric and physical fitness measurements were obtained by physical education teachers.
A greater proportion of males than females (42.3 percent versus 37.3 percent) and of children compared with adolescents (42.1 percent versus 32.8 percent) reported insufficient sleep duration. Adolescents with an insufficient sleep duration also had lower aerobic fitness and physical activity.
"The most surprising finding was that aerobic fitness was associated with sleep habits," said Sidossis. "In other words, better sleep habits were associated with better levels of aerobic fitness. We can speculate that adequate sleep results in higher energy levels during the day. Therefore, children who sleep well are maybe more physically active during the day and hence have higher aerobic capacity."
The authors noted that the results support the development of interventions to help students improve sleep duration.
"Insufficient sleep duration among children constitutes an understated health problem in Westernized societies," Sidossis said. "Taking into consideration these epidemiologic findings, parents, teachers and health professionals should promote strategies emphasizing healthy sleeping patterns for school-aged children in terms of quality and duration."
https://www.sciencedaily.com/releases/2018/11/181112191814.htm