Two new studies highlight the importance of sleep for teen health.

The first, done by researchers at the University of British Columbia and published in Preventative Medicine, studied B.C. students aged 13 to 17 over two years and found that chronic, low-quality sleep was related to poorer health.

“Even if they had difficulty falling asleep just one night a week, if that was a regular occurrence over two years, it really seemed to affect their overall health,” said Annalijn Conklin, study author and assistant professor of pharmaceutical sciences at the University of British Columbia in a school press release.

Researchers found that the relationship between low-quality sleep and poorer health was stronger in boys than in girls – but overall, whether the students received enough sleep seemed less of a factor than the quality of the sleep they did get.

“It does signal that cumulative sleep problems matter for the health of young people,” said Conklin.

“It shows that there’s definitely a link between poor health and chronic poor-quality sleep which may be gender specific.”

The second study, published by the American Psychological Association (APA), found that “teens who don’t get enough sleep may be at increased risk to engage in risky sexual behavior” such as having unprotected sex or having sex under the influence of drugs or alcohol.

“Insufficient sleep may increase the potential for sexual risk-taking by compromising decision-making and influencing impulsivity,” said lead study author Dr. Wendy Troxel in a press release.

The research analyzed data from a long-term study of 1,850 teens and young adults in southern California between 2013 and 2017.

The teens reported their sleep schedules on weekdays and weekends, whether they used alcohol, cannabis or other drugs right before or during sexual activity and whether they used condoms.

Prior research indicated that irregular sleep patterns can negatively affect teen health, so the APA expected that teens who slept for longer on weekends to make up for lost hours during the week to show greater propensity for risky sexual behavior.

Instead, the researchers were surprised to find that teens who consistently did not get enough sleep on both weekdays and weekends were “two times more likely to engage in unsafe sex” than those who caught up on sleep on the weekends.

Unlike the other study, the APA found that sleep quality did not have any effect on risky sexual behavior, but rather it was a question of quantity.

“Our recommendation is for parents and teens to find a middle ground which allows for some weekend catch-up sleep, while maintaining some level of consistency in sleep-wake patterns,” said Troxel.

The study also recommended schools delay their start time in the morning to encourage teens to get adequate sleep.