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Jesse Itzler is an entrepreneur several times over, most notably with Marquis Jet, which he sold to Berkshire Hathaway, and Zico coconut water, which he sold to Coca-Cola. He's also an extreme distance runner with a 100-mile race to his credit and the husband of Sara Blakely, the billionaire founder of Spanx.

If there's one thing he's not, it's boring. So when he was worried that he was stalling a bit--falling into a routine--he did something kind of crazy. He recruited a U.S. Navy SEAL to live with him for a month and to break him out of his rut.

"I met him at a race, and I had never seen anything like it. He was so locked in, and I wanted something he had," says Itzler, whose book about the experience, Living With a SEAL: 31 Days of Training With the Toughest Man on the Planet, is out today. "So I hired the guy."

If you don't know much about the SEALs beyond the movies--think American Sniper, for example, the real-life story of the late Chris Kyle--the short version is that they're among the fiercest and most-deployed special operations troops in the U.S. armed forces. Their initial training, which lasts a total of 50 weeks, is some of the hardest in any military in the world.

Here are the top things Itzler's warrior-tutor taught him about living an exceptional life--all while staying with him in a posh apartment on the Upper West Side of Manhattan. (Want to read more, make a suggestion, or be featured in a future column? Contact me or sign up for my weekly email.)

1. Get your butt out of bed.

Itzler's mentor, who had served multiple tours in Afghanistan and Iraq and had lost friends in combat, wanted to remain anonymous, so he's referred to simply as the SEAL in the book. He and Itzler trained whenever the SEAL wanted to. Often, that meant the middle of the night during a cold New York City December.

In part because they got up so early, Itzler says he found he had so much more time to accomplish things during the day: "I felt like everyone else was on a 24-hour day and we had 27."

2. Make the bed.

I was a little amused to hear this one, because making your bed the first piece of advice that Admiral William McRaven, the SEAL officer who commanded the raid that killed Osama bin Laden, gave in an oft-cited speech. It turns out the SEAL started his day the same way.

"He created a habit and pattern on everything he did--little things like making the bed, to being on time, to perfecting technique and form," Itzler explains. "It's hard to be late or come up with excuses when you're around someone living life like that."

3. Be a consistent minimalist.

The SEAL was finishing his active-duty career at the time he moved in with Itzler and family, using his accumulated leave from the military (basically vacation) to do so. One of the most surprising things, Itzler says, was how simply he lived.

"He showed up for 31 days with a backpack, his ID, and a debit card. If I went away for 31 days, I'd have five suitcases." Beyond that, he added, "he was the most consistent guy I ever met. No days off. No interruptions. He was disciplined and consistent."

4. Do. Not. Quit.

We all quit. Sometimes I think it's a good thing. Maybe that's why I'm not a Navy SEAL.

"He had all these 'SEALisms,' like: 'If your brain says you're done, you're only 40 percent done,'" Itzler recalls. "So many times physically at work, in negotiations, when I've got deal fatigue, he'd have this incredible energy. There's always more in your reserve tank."

5. Screw your comfort zone.

This seems to be a big part of the SEAL's theory. In short, the idea is that it's only through discomfort and pain that you have the opportunity to grow. It might be that pain is not simply a byproduct of growth, but part of its cause as well.

"I was physically pushed out of my comfort zone every day. To jump start the concept, I slept in a wooden chair the first night. I think he took it a little too literally," Itzler says. His mantra was: "If it doesn't suck, we don't do it."

6. Wait it out.

Anyone who's served a day in the military--even in much less demanding jobs--knows this part. Patience isn't just a virtue; it's an absolute necessity, if you want to succeed. And Itzler says that one of the surprising things that happened to him was that he grew more patient as a result of his month of training.

"I became incredibly patient--even sitting in traffic. it. The secret is knowing that everything ends. We'd do these incredible training routines, and he'd focus me on that fact to get through it: It's going to end. Eventually, everything ends," Itzler recalls.

7. Strip out the nonessentials.

This one probably makes sense for a guy who showed up for a month in winter with nothing but a single small backpack, but Itzler said his SEAL mentor taught him to clear his mental clutter as well.

"He made me eliminate all the nonessential things," he recalled. "He'd give me a call and be like, you don't need to do that or return those emails. We're going for a run. And I wouldn't--and nothing suffered. I was so scared [to break the routine], but in fact I became way more efficient."

8. Seek the harder challenge.

Ultimately, the SEAL's methods aren't just about discomfort, or minimalism, but about seeking tougher challenges for the sake of the challenges themselves.