Dr. Michael Grandner

And actually, if you ask people how well rested you think you are, but you see how much sleep they're getting, it's how much sleep they're getting, not how well rested they think they are that predicts drowsy driving, for example.

Like even if you say you're fully well rested, if you're getting five or six hours of sleep, you are three times as likely to nod off behind the wheel.

Even if you say I am 100% well rested, data don't bear that out.

People are not a good judge of how impaired they are due to sleep deprivation.

So...

How much sleep you get is important in terms of those sorts of things.

In terms of athletics injuries, what seems to be a bigger driver actually are two variables, insomnia and daytime sleepiness, which are very common in college students.

But actually, if you're sleepy during the day, even if you feel like you're getting plenty of sleep at night, if you're nodding off during the day, if you're having trouble staying awake,

you're more likely to hurt yourself.

You're more likely to wink out.

You're more likely to like not focus on something.

You're more likely to hurt yourself.

Same thing if you have really bad insomnia, irrespective of how much sleep you're getting, that inability to sleep when you're trying is predictive.

So one example, so we did...

Probably what is like the biggest controlled study of this, where what we did was we, again, went into a division one school, measured everybody over the summer before they showed up for classes and training.

And then we just combed through every interaction with any health care person.

And in this school, everything from I feel stressed to I twisted my ankle gets documented in their record.

Everything.

Every headache gets documented.

So we just combed through to see what over the summer predicted concussions.