When College Classes Start Late, Students Sleep and Drink More — and Get Worse Grades

At first glance, it sounds like the perfect solution to the student sleep crisis: start college classes later in the morning so students can get more rest. In theory, better-rested students should have sharper focus, stronger memory, and improved academic performance. And in some studies of high schoolers, that’s exactly what happens.

But research on college students paints a more complicated picture. In some cases, later class start times are associated not with better grades, but with worse grades — despite students sleeping longer. The difference lies in what students do with that extra flexibility and how college culture shapes their habits.

The Promise of Later Starts

Sleep scientists have long known that young adults, like teenagers, have a natural tendency toward later bedtimes and wake times. In high school, early start times often force students to wake before their biological clock is ready, leading to chronic sleep deprivation.

College seems like the ideal place to fix this: if students can choose later classes, they can sleep closer to their natural rhythms. On paper, this should mean:

• More total hours of sleep

• Better mood and alertness in class

• Stronger academic performance

And indeed, surveys confirm that students with later classes often report getting more sleep — sometimes an hour or more extra compared to their peers in early sections of the same course.

The Paradox: More Sleep, Lower Grades

However, large-scale studies have found that college students who take later classes often have lower GPAs than those with earlier schedules. A notable example is a University of Washington and University of California, Santa Barbara analysis, which showed that students with later first classes went to bed later, slept later, and engaged in more late-night activities — including drinking — that negatively affected academic outcomes.

Here’s the paradox: while these students may sleep longer, the timing of their sleep and their overall lifestyle may be less compatible with optimal learning.

Why Later Starts Can Backfire in College

1. Shifted Sleep Schedule

When the first class isn’t until 11:00 a.m. or later, many students push bedtime into the early morning hours. They still get their 8 hours — but much of that sleep occurs in a delayed cycle that can interfere with morning alertness and alignment with the day’s demands.

2. More Time for Late-Night Socializing

A later start means less pressure to wind down early. Parties, bar nights, and dorm hangouts can stretch into the small hours, with students feeling less need to cut themselves off because they “don’t have to be up early.” This can increase alcohol consumption and reduce sleep quality, even if total sleep time is higher.

3. Increased Alcohol Use

Multiple studies link later first classes with higher drinking rates among college students. The reasoning is simple: fewer morning obligations lower the perceived cost of staying out late and drinking. Unfortunately, alcohol disrupts the second half of the sleep cycle, leading to lighter, more fragmented rest that’s less restorative.

4. Lower Structure and Discipline

Early classes can serve as an anchor for the day — a reason to get up, get moving, and start on assignments earlier. Without that anchor, some students procrastinate on both waking up and starting work. Evenings fill with social activity, while afternoons may be spent catching up on sleep or idly passing time, leaving less total time for focused study.

5. Delayed Learning Window

Cognitive performance has daily rhythms, and for many people, attention and memory are strongest in the late morning. Students who push their academic work later in the day may be working during a lower-performance window, particularly if they’re also staying up past midnight.

The Role of Personal Responsibility

The impact of late starts varies by student. Self-disciplined students who use the extra rest to fuel productivity may see benefits. But for those still adjusting to the independence and distractions of college life, later classes can feed into a cycle of:

• Staying up late → Sleeping late → Less time for daytime study → Increased evening socializing → Staying up late again

This cycle isn’t inevitable, but it’s common — especially among younger undergraduates.

Alcohol, Sleep Quality, and Academic Performance

Even moderate alcohol use before bed can reduce the proportion of deep slow-wave sleep and REM sleep. For students in the “late start” group who drink more frequently, the benefits of longer sleep may be offset — or erased — by poorer sleep quality.

Poor-quality sleep leads to:

• Slower information processing

• Reduced working memory capacity

• Weaker problem-solving skills

• More difficulty concentrating in lectures

When those effects stack up over a semester, grades can take a noticeable hit.

What the Research Suggests

Several key findings emerge from the research on this topic:

• Later first classes = later bedtimes. Students rarely use the extra morning time to get more early sleep.

• Alcohol use increases. The absence of morning obligations removes a deterrent to late-night drinking.

• Grades can drop. The combination of later bedtimes, lower-quality sleep, and lifestyle changes appears to outweigh the benefits of extra rest for many students.

One study even found that for each hour a student’s first class started later, their GPA was slightly lower — largely explained by differences in sleep timing and alcohol use.

Navigating the Trade-Off

This doesn’t mean late classes are inherently bad — but it does mean students and educators should be aware of the trade-offs.

For students:

• Treat a late start as an opportunity for better rest and earlier academic work, not just more social time.

• Maintain a regular bedtime, even on nights without early obligations.

• Watch for creeping increases in alcohol use and late-night activity.

For colleges:

• Offer education on sleep hygiene and the risks of excessive alcohol use.

• Encourage balanced scheduling that avoids both extremely early and very late first classes.

• Provide quiet study spaces in the mornings to encourage productive use of time.

The Bottom Line

Late-start college classes offer the promise of more sleep — and in theory, more alert, higher-performing students. But in practice, the freedom they offer can lead to later bedtimes, more drinking, and weaker daily structure.

For some students, that means worse grades, even with extra rest. The lesson isn’t that late starts are bad for everyone, but that their success depends on how students use the flexibility. Sleep isn’t just about quantity; it’s about timing, quality, and the lifestyle choices that surround it.

In the end, the best academic results come when students combine healthy rest with consistent habits — whether their first class is at 8:00 a.m. or noon.

This article was created using OpenAI’s ChatGPT on August 15, 2025 and it was personally reviewed and edited by Brandon Peters, M.D. to ensure its accuracy. This use of augmented intelligence in this way allows the creation of health information that can be trusted.