Teens can improve sleep quality with exercising

Washington: Exercising is not only limited to a person's physical well-being but also affects their sleep health. A new study claims that teens who engaged in physical activity tend to sleep longer and better. In the study published in the journal Scientific Reports, researchers found that every extra hour of moderate-to-vigorous physical activity made the teens fell asleep 18 minutes earlier, slept 10 minutes longer and had about one per cent 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 behaviours," said Lindsay Master, a 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."

To the contrary, the study also leads to a finding that being more sedentary during the day was liked to 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 at Penn State, said, "You can think of these relationships between physical activity and sleep almost like a teeter-totter."

"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."

For this study, the researchers used data from 417 participants. 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 behaviour, which can sometimes be skewed," Master said.

He added, "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."

Researchers also found that when participants slept longer and woke up later, they engaged in less moderate-to-vigorous physical activity and sedentary behaviour the next day.

Adding on this finding Bruxton added, "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."

"We were able to show that the beneficial effects of exercise and sleep go together and that health risk behaviours like sedentary time affect sleep that same night."