College is a time of personal discovery, academic development, and just plain fun. But one thing it generally isn't, is a period in life when you get a ton of sleep. Between late night study sessions, early morning classes, and irresistible parties, there are a million and one reasons college kids don't generally prioritize sleep.  

But if college students are hoping to actually learn something and have the grades to prove it, they may want to rethink their lackadaisical approach to sleep, according to surprising new research out of MIT. 

The best study tool is your bed. 

The results of the study were so surprising, in fact, that they even managed to shock the team behind the research. The whole project got started when MIT professor Jeffrey Grossman decided to look into a possible link between how much the students in his solid-state chemistry class exercised and the grades they got. To figure out the relationship, he asked 100 students to wear Fitbits for the semester and enrolled 25 of them in an intensive fitness program. 

Did hitting the gym lead to better grades in chem? The answer turned out to be no (though you should probably hit the gym anyway for about a million mental and physical health reasons). But that doesn't mean the study was a bust. When Grossman and his collaborators crunched the data, another clear correlation popped out. 

When the team plotted how much sleep students got against their grades, a straight-line relationship emerged. The more a student slept, the better they did in Grossman's class. That's not terribly surprising. It's hard to learn when you're half-asleep from last night's rager. But according to Grossman the strength of the relationship was a shock. 

Sleep "really, really matters," he commented

And, sorry night owls, club kids, and video game addicts, so does your bedtime. The numbers also showed that even if you get plenty of sleep, if you go to bed after 2 a.m. your academic performance is still going to suffer. Along similar lines, keeping a relatively consistent bedtime routine rather than having your bedtime swing around erratically was also correlated with better grades. 

But don't stress if you have pre-test insomnia. 

The strength of the connection between good quality sleep and a student's final grade wasn't the only shock the team fished out of the Fitbit data. They also discovered good news for last minute crammers everywhere. While more sleep throughout the semester had a huge impact on performance, more sleep the night before a big test did not. 

"The night before doesn't matter," Grossman says. "We've heard the phrase 'Get a good night's sleep, you've got a big day tomorrow.' It turns out this does not correlate at all with test performance. Instead, it's the sleep you get during the days when learning is happening that matter most."

Which means that if your nerves have you up the night before your big exam, don't freak out. You're not doomed to fail. But also don't think that simply cramming all your learning into one marathon late-night study session is going to work either. Pre-test insomnia doesn't matter because most of the learning for a test happens way before that last night. 

You're not going to be able to shove everything you need to know into your head in one night, but you're also not going to blow your test if you don't sleep like an angel the night before. 

That's the good news for sleep-deprived college students. But it's the only good news in this study. Otherwise the message is crystal clear: if you want to do well at university, put all those stereotypes of college students stumbling home at 4 a.m. out of your head (most days) and actually get some rest. Bad sleep leads straight to bad grades.