The tech titan is known for getting up early. According to a Time profile, He wakes up at 3:45 every morning ('Yes, every morning'), does email for an hour, stealing a march on those lazy East Coasters three time zones ahead of him, then goes to the gym, then Starbucks (for more e-mail), then work. 'The thing about it is, when you love what you do, you don't really think of it as work. It's what you do. And that's the good fortune of where I find myself.'While the president is known for getting very little sleep, he's got nothing on the first lady, who tells Oprah she starts her days with a 4:30 a.m. workout before her kids wake up. If I don't exercise, I won't feel good. I'll get depressed, she says, noting that it's easier to pull that off at the White House, where she has much more support than the average person. The former Google executive tells The Guardian that he's not a big sleeper and wakes up at 5 a.m. or 5:15 a.m. every day to work out, read, tinker with the site, and hang out with his middle daughter, who is also an early riser. Armstrong says he tries to hold off on sending emails until around 7:00 a.m.Burns uses early morning hours to get caught up on emails, getting up at 5:15 a.m. and sometimes working until midnight, according to Yahoo Finance. She also uses the time to fit in a workout, according to Laura Vanderkam's What The Most Successful People Do Before Breakfast. Burns schedules an hour of personal training at 6 a.m. twice a week. Immelt tells Fortune that he gets up at 5:30 in the morning every day for a cardio workout, during which he reads the papers and watches CNBC. He claims to have worked 100-hour weeks for 24 straight years. Nooyi wakes up as early as 4 a.m., telling Fortune that they say sleep is a gift that God gives you ... that's one gift I was never given. In a speakers series at Pepsi, she reveals that she is at work every day by no later than 7 a.m.The standing desk company leader tells TechInsider he wakes up at 3:30 a.m. It's not for everyone, he says. The first thing Lee does when he wakes up is drink two liters of water followed by two cups of coffee and a smoothie. Then he spends 30 minutes with his dog followed by an hour of reading time. By 5:15 a.m., Lee is at the gym, where he works out until 6:15 a.m. He spends the next hour showering, shaving, and traveling to his office, and by 7:15 a.m., he's ready to start the workday.According to New York Magazine, the Twitter cofounder wakes up at 5:30 a.m. to meditate and go for a six-mile jog.Marchionne wakes up at 3:30 a.m. to deal with the European market, according to a 60 Minutes profile on his turnaround of Chrysler. Referring to his schedule and work ethic, one exec is quoted in the FT as saying: Sergio invented an eighth day, and we work it. In that 60 Minutes special, another exec says: When it was a holiday in Italy he'd come to America to work. When it's a holiday in America he goes to Italy to work. Good investors don't stay in bed in North America with strings untied overseas, because if something happens in London or Tokyo while they're sleeping, everything can change, the investor writes in a post for Business Insider. After checking the bond markets, O'Leary gets on the elliptical or exercise bike and watches business television for 45 minutes while he works out. This is followed by an hour of reading and business research, and then he heads to work by market open at 9:30 a.m.In an interview with Business Insider's Aly Weisman, Branson reveals that he wakes up at about 5:45 in the morning, even when staying at his private island, leaving the curtains drawn so the sun gets him up. He does his best to use those early hours to exercise before an early breakfast and getting to work. Like her predecessor, Daniel Akerson, GM's current chief executive is an early riser. According to a New York Times profile, she was regularly at the office by 6 a.m. before she even became CEO.Gross, now a portfolio manager at Janus Capital in Denver, starts his day early — really early. According to Fortune, he wakes up at 4:30 in the morning to check out the markets and gets into the office by 6 a.m. In a post for Business Insider, the Hint Water founder says she's up at 5:30 a.m. on the dot, to look over her calendar, catch up on unread emails, and make sure nothing urgent has popped up over night. Once that's done, she sips a double latte and takes a morning hike with her husband and dogs before making her first work-related call at 7:15. Cush describes his morning routine to the AP. He wakes up at 4:15 a.m., sends emails, calls business associates on the East Coast, and that's before listening to Dallas sports radio, reading the paper, and hitting the bike at the gym.The online-only retail company for kids kicks off every morning with a 6 a.m. (Pacific Time) sale. That's when its chief executive gets a notification on his phone, which serves as his alarm. Part of my night routine is to look at a preview of what the site’s going to look like the next day — so the very first thing I do is pull up the site on my phone to make sure they match, he tells Inc.The former Citigroup CFO writes in a LinkedIn post that she's never more productive than she is at 4 a.m. I brew a cup of coffee, I keep the lights pretty low, I sometimes light a fire in the fireplace, and I let my daughter's cat sleep next to my computer, she writes. That's when her mind is clearest, she explains, since she's not yet caught up in the day's internal conversations. Perhaps not unrelated, it's also when she finds she's the most creative. It is at this time of day that I often have a rush of ideas (some of them actually good).Schultz starts his day with a workout, which is usually a bike ride with his wife, but still gets to the office by 6 a.m., according to Portfolio.com.The fashion icon starts his days at 5:30 a.m. with an espresso, which he sips while reading the newspaper, he tells the New York Post. He's a big fan of those early morning hours. I love getting up before the sun's up, he explains, telling The Times that he starts even his Sundays with 50 sit-ups, in bed. According to The Guardian, he exercises then works to about 10:45 p.m., with a small gap for dinner with his family. He heads to bed by 11:30 p.m.The cofounder of Kayak and travel startup Blade tells Inc. he wakes up by 6 a.m. I usually meditate for a few minutes to quiet my mind before I get out of bed, he says. I get up around 6 every morning. After I check email on my BlackBerry, I go exercise. I've been practicing yoga for about 10 years. I built a meditative room in my house.