Experts recommend that teenagers get 9.2 hours of sleep per night, but many teenagers do not get enough sleep. The document summarizes research showing a correlation between less sleep and lower grades in teenagers. Teenagers' internal clocks change during puberty, making it difficult for them to fall asleep early, and factors like homework and early school start times can further reduce teenage sleep. Getting the recommended 8 to 10 hours of sleep per night is important for teenagers' health, awareness and academic performance.