04/29/2014 08:40 am ET Updated May 08, 2014

How Much Sleep Katie Couric, Kenneth Cole And 7 Other Leaders Get At Night

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There's a reason why study after study (after study) has shown that getting a good night's sleep is one of the absolute best things you can do for your mind and your body. "You have an opportunity to immediately improve your health, creativity, productivity and sense of well-being by getting just 30 minutes more sleep tonight than you got last night," HuffPost President and Editor-in-Chief Arianna Huffington explained at The Huffington Post's Thrive conference last week.

Given that sleep and success so often go hand-in-hand, we asked several of the seriously accomplished speakers at the Thrive event to let us in on their bedtime habits. Most, it turns out, prioritize getting plenty of high-quality sleep a night, though a few copped to scrimping. (Good thing that adding just 30 minutes per night can make such a big difference, eh?)

Here's how many hours these 9 leaders clock at night:

I am kind of fanatical about trying to get at least seven or eight -- mostly eight. Last night, I got seven-and-a-half, so I was on the edge.
--Dr. Mark Hyman, M.D., Authority in Functional Medicine; Founder, The UltraWellness Center

--Katie Couric, Award-winning Journalist, TV Personality and NY Times Best-selling Author

I get probably five to six hours a night. The key to me is not just how much sleep I get, but when I sleep. I try to go to bed the same time and get up the same time every day. It makes an enormous impact on your mind.
--Dr. David Agus, M.D., Professor, USC Keck School of Medicine and Viterbi School of Engineering; CBS News Contributor

I try and get seven hours every night. I've found that since I had my son, I actually do that more often. Taking him through his bedtime routine around 7 p.m. relaxes me, so I feel like I'm able to go to bed earlier. Before, I would've procrastinated and found things to do until 2 a.m.
--Randi Zuckerberg, Founder and CEO, Zuckerberg Media; Editor-in-Chief, Dot Complicated

Four to five. It’s more than three or four, and I’m much more functional when I get five, than four. But I don’t usually use an alarm clock to get up. It’s this inner clock that gets me up out of bed in the morning.
--Kenneth Cole, Chariman & CEO, Kenneth Cole

Through choice, I get around six to seven. If I get too many, I actually don't feel great. I purposely set the alarm to wake up after six or seven hours.
--Andy Puddicombe, Headspace Co-Founder

I sleep about seven hours -- eight would be better. But I wake up, no matter where I am, at 6 or 6:30 a.m.
--Laurie David, Author and Producer

Last night I got about five-and-a-half, but that is not a good enough amount. I always say, "Invest in tomorrow by going to bed earlier tonight." You can stay up and watch reruns of "Friends," or do stupid things on your computer, but tomorrow you're going to be wiped out. Seven hours is good for me.
--Lucy Danziger, Former Editor-in-Chief, SELF Magazine; Well-being Lifestyle Expert

Eight hours, 10 hours. I love sleep, it's one of my favorite activities. I attribute sleep to my success.
--Panache Desai, Spiritual Teacher

These interviews have been edited and condensed for clarity and length.