Step aside Elon Musk, there's another CEO superhero in Silicon Valley.

Over recent days, Jack Dorsey was named permanent CEO of Twitter, launched one of the company's boldest features in years, and announced plans to lay off about 8 percent of Twitter's work force. And that's just at one of his companies. Square, a payments startup he founded and runs, just announced it is filing to go public.

It's an amazing turn for Dorsey, who was quietly pushed out as CEO of Twitter in 2008 for reportedly leaving work habitually at 6 p.m. to take drawing classes and do hot yoga. If his public statements and interviews reveal anything, it's that he's changed his ways.

Dorsey isn't the first to juggle two major companies at once. Steve Jobs simultaneously ran Apple and Pixar, and Elon Musk helms both Tesla and SpaceX. But many people close to the action say it's suboptimal.

Square's IPO filing acknowledged as much: "Our future success is significantly dependent upon the continued service of our executives ... [Dorsey's dual leadership roles] may at times adversely affect his ability to devote time, attention, and effort to Square." Musk chimed in, telling the audience at the Vanity Fair Summit, "I wouldn't recommend running two companies ... It decreases your freedom a lot."

Here's a peek at Dorsey's productivity habits:

1. Make time for planning and reflection.

"The best thinking time is just walking," Dorsey told Forbes in 2012. He starts his days with three- to five-mile runs, and takes new recruits on tours of San Francisco. He takes off Saturdays to hike and spends Sundays planning for the week ahead.

2. Give each day a theme.

In 2012, Dorsey told Techonomy's David Kirkpatrick that, when he was originally splitting his time between the two companies, he would designate certain tasks for each day of the week. The breakdown:

  • Monday: Management
  • Tuesday: Product
  • Wednesday: Marketing/communications and growth
  • Thursday: Developers and partnerships
  • Friday: Culture and recruiting

"There are interruptions all the time," Dorsey said. "But I can quickly deal with an interruption and know it's Tuesday--I have product meetings and I need to focus on product stuff. It also sets a good cadence for the rest of the company."

3. 100-hour workweek.

In the same interview, Dorsey casually mentioned he spends eight hours a day, six days a week at each company. Luckily, he lives within walking distance of his offices.