12 successful tech executives who wake up really early

Marissa Mayer isn't much for sleep. The Yahoo CEO presumably wakes up early since she says she only gets between four and six hours of sleep on any given night.

Tim Cook, Apple's CEO, starts sending emails around 4:30 a.m., according to Gawker's Ryan Tate. After that he works out. He's boasted about being the first in the office and the last out.

Maybe Tim Cook fashioned his early morning routine after his former boss, Steve Jobs.

Jobs told Time back in 1999 about how he started his days: "I'll wake up sixish and work a little before the kids get up. Then we'll have a little food, finish up some homework and see them off to school. If I'm lucky I'll work at home for another hour, but oftentimes I'll have to come in. I usually get [to Apple] about nine. Eight or nine. Having worked about an hour and a half or two hours at home."

Dorsey described his morning routine to New York Magazine, revealing that he wakes up at 5:30 a.m. to meditate and go for a six-mile jog.

He kept up that routine during a period where he shuttled back and forth between Square and Twitter, spending around 8 hours a day at both companies.

Jeff Jordan, formerly of PayPal and OpenTable, now works for Andreessen Horowitz and leads deals incompanies like Fab and Pinterest.

Prior to joining A16Z, Jordan told The New York Times that he got into the office by 5 a.m., and didn't leave until after 7 p.m.

One of the most well-known women in business today, Cisco's former CTO Padmasree Warrior's morning routine consists of waking up at 4:30 a.m., reads her email for an hour, checks out the news, exercises, and preps her son for school — all before 8:30 a.m., according to Yahoo Finance.

Warrior was also formerly the CTO of Motorola.

Tim Armstrong wakes up so early, he has to hold himself back from sending emails and interrupting the morning habits of others (i.e. sleeping).

The AOL CEO tells The Guardian he wakes up at 5:00 or 5:15 a.m. and starts sending emails around 7:00 a.m. During those two hours, Armstrong exercises and reads. He also chats with his middle daughter, who is an early riser.

"I am not a big sleeper and never have been. Life is too exciting to sleep," Armstrong tells The Guardian.

Burns uses early-morning hours to get caught up on emails, getting up at 5:15 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.

Hans Vestberg, CEO of Ericsson, rarely arrives at the office past 8:00 a.m. When asked how early he wakes up he simply says, "early."

Before he goes to work, Vestberg works out and sends emails. His company's nights and days morph into each other; it's always working. Vesberg goes to bed "quite late" but says he gets enough sleep.

"Our company never sleeps: we have business in 180 countries, so there are no real mornings or nights," he tells The Guardian.

Vittorio Colao wakes up at 6:00 a.m, according to The Guardian. He exercises then works through about 10:45, with a small gap for dinner with his family. He heads to bed by 11:30 p.m.

Paul English, co-founder 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 e-mail on my BlackBerry, I go exercise. I've been practicing yoga for about 10 years. I built a meditative room in my house."

Zulily, an online-only retail company for kids, kicks off every morning with a 6 a.m. (Pacific) sale.

That's when its creator, Darrell Cavens, 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.