How to Stay Awake in Class When You Are Running on Empty

To stay awake in class, protect your sleep first: a later school start went with more sleep and lower sleepiness in one small study. In that non-randomized study of 51 14-year-olds, the class that gained about 34 minutes of sleep over the year reported less sleepiness at the end. For today, naps and morning light have limited support.

No study here promises a thirty-second fix. Most of the research below is small, done on adults in labs, or based on surveys, and we say so each time. Where it has nothing to say, as with caffeine, we leave the gap open.

How much sleep do teenagers and college students actually need?

Adolescents need about 8.5 to 9.25 hours a night, according to a National Sleep Foundation figure cited in a 2016 review of delayed sleep phase disorder in Nature and Science of Sleep. The same review reports that average sleep is only 7 hours 42 minutes at age 13 and 7 hours 4 minutes at age 19. That review pools no data, so treat the numbers as a reference range.

For adults, including college students, Binjabr and colleagues in Current Sleep Medicine Reports (2023) use a 7 to 9 hour guideline. Their medical students averaged only 6.5 hours a night.

Check your own number. Count the hours between lights-out and your alarm for the past week. If you are a teenager and the answer is 8, you sit below your range.

How many students are excessively sleepy during the day?

Binjabr and colleagues pooled 109 studies of 59,427 medical students. Across the 28 studies that measured sleepiness (10,122 students), 33.32% reported excessive sleepiness during the day. Poor sleep quality was more common still, at 55.64% across 95 studies. The authors note that the studies differed widely.

In 2025, Hou and colleagues surveyed 1,658 nursing students at 8 schools in 5 regions of China. They found that 18.03% (299 students) had excessive daytime sleepiness. Internet addiction had the strongest link (odds ratio 4.401, 95% CI 3.166 to 6.117), followed by psychosomatic illness (2.970), clinical practice (1.991) and drinking (1.603). A cross-sectional survey cannot show cause, and the answers were self-reported.

Neither group covers every student, but you are in large company.

Why do I get so sleepy in class even after sleeping 8 hours?

Eight hours can still be short, and an early alarm can cut into it. If you are a teenager, 8 hours sits below the 8.5 to 9.25 range above. Falling asleep late, around 11 p.m. in that review, leaves little room before school.

Alfonsi, De Gennaro and colleagues (2020) tracked 51 high-school students whose classes started at 8:00 or 9:00 a.m. Both groups turned their lights off at similar times (about 11:11 and 11:21 p.m.), but the 8:00 class woke at 6:55 a.m. and the 9:00 class at 7:23 a.m. The early start went with less sleep. Students chose their own class, so the groups may have differed beforehand.

In the nursing survey, clinical practice and internet addiction were also tied to sleepiness. If late nights on a screen are your pattern, our guides on why you cannot go to bed with ADHD and revenge bedtime procrastination cover the pull to stay up.

Do later school start times help students stay awake?

In the Alfonsi study, a one-hour later start went with about 34 more minutes of sleep (34.1 ± 11.9 minutes) over the school year. The 8:00 class slept about the same as before. By the end of the year, the 9:00 class reported lower daytime sleepiness (p = 0.03), and the authors associate the later start with better sustained attention and attendance. The design was non-randomized, the sample small, and the early class scored higher on the entrance test.

A 2024 systematic review in Sleep Advances by Gaskin and colleagues looked at 21 randomized trials (22 papers, 10,867 children and adolescents in 13 countries). It found that sleep education lessons were typically ineffective. The interventions were short, a median of 4 weeks. Only one study tested later start times, which promoted longer sleep over 1 week and was rated high risk of bias.

If you pick your own sections in college, the Alfonsi result is a reason to weigh class times when you register, with the caution that those students were 14.

Lessons usually did not change sleep in the review, so our suggestion is to work on what you repeat each night. A buddy on GetMotivated.ai can be the person you text when lights are out, and a challenge with a daily check-in turns "sleep more" into one small thing you report on.

Is a nap before or between classes a good idea, and how long should it be?

A nap can help alertness, and earlier in the afternoon looks better. Dutheil and colleagues (2021) ran a systematic review and meta-analysis in the International Journal of Environmental Research and Public Health. It covered 11 studies of 381 working-aged adults, nearly all in laboratories. Cognitive performance improved after a nap (effect size 0.18, 95% CI 0.09 to 0.27), most of all alertness (0.29, 0.10 to 0.48). Naps before 1 p.m. looked better (0.24), though that estimate was imprecise (95% CI -0.07 to 0.34).

The limits are large. These were adults, not students, and the average nap lasted 55.4 minutes, far more than most people can fit between lectures. Results during the foggy stretch right after waking, called sleep inertia, were conflicting. The control group relaxed instead of working, which the authors say could understate the effect.

If you try a nap, treat it as a test. Pick a day without an exam, set an alarm, leave a buffer before class, and note how you feel on waking.

Does bright light or sitting by a window help you stay alert?

Two small adolescent studies tested morning light, and neither tested a window.

Teicher and colleagues (2023, PLOS ONE) gave 26 sleepy adolescents aged 13 to 18 a 30-minute bright light device each morning for 3 to 4 weeks. They also wore blue-light-blocking glasses for 2 hours before bed. It was an open, non-randomized trial with no placebo or sham light, so the glasses and light cannot be separated. Participants used the device 57% of the recommended time. More use went with a 22% drop in response-time variability on an attention test and was linked to 19.2% of the variance in change in math scores. Sleep onset and duration did not change.

A 2025 experiment in Frontiers in Behavioral Neuroscience put 47 adolescents aged 15 to 21 through a single 30-minute morning bright-light session (24 well-rested, 23 sleep-deprived). Negative mood and a forward digit span task improved after the light, but subjective sleepiness did not change. The authors say the lack of a control light limits what the result proves.

Morning light has early signals and no proof, and it is no quick fix for the next ten minutes. A seat near a window costs nothing to try as your own experiment.

Does caffeine actually help you stay awake in class, and when should you stop?

We cannot answer that from the research behind this post. None of the eight studies tested caffeine, coffee or energy drinks as a way to stay awake, so we give no dose, no cutoff hour and no verdict on energy drinks.

If you already use caffeine, read the label for the amount per serving, and ask a pharmacist or clinician what suits you, particularly if you take any medication. Then log the time of your last caffeinated drink next to how you slept that night.

When is constant daytime sleepiness a sign of a sleep disorder?

These studies cannot say when sleepiness crosses from ordinary to a disorder. The 2016 review of delayed sleep phase disorder (DSPD) says adolescent prevalence estimates exceed 7%. DSPD means sleep comes much later than the bedtimes school and work expect, and it is diagnosed when symptoms cause distress or impairment and persist for at least 3 months.

The review also cites a study of 22 adolescents with DSPD in which 59% showed poor scholastic performance and 45% had behavioral problems. That is a very small sample, so read it as a warning sign, not a rate.

None of the eight studies examined narcolepsy or sleep apnea as a cause, so we describe no signs for them. The 3 months is a diagnostic criterion, not a waiting period, and a doctor or your campus health service is the place to raise sleepiness that is not improving. Our guide to delayed sleep phase explains the pattern.

What can I do in a lecture to stay awake without being obvious?

None of the moves below was tested in the studies above, so treat them as experiments and keep the ones that work for you.

Sit where the light is. A seat near a window is a cheap way to try the idea behind the light studies, though none of them tested one.

Move quietly. Sit upright, press your feet flat, and shift position every few minutes.

Stay busy with the content. Write one sentence at the end of each section, or a question to ask. Our guides on how to study with ADHD and what to do when you cannot focus while studying go deeper on staying with the material once you are awake.

Keep score. After each class, rate your sleepiness from 1 to 5 and note the hours you slept the night before. After a week, you have your own data to compare with the studies and to show a clinician if the pattern holds.

For the next ten minutes, count back from your alarm by the hours in your range (7 to 9 for adults, 8.5 to 9.25 for teenagers), then set a lights-out alarm on your phone for tonight.