Entrepreneurs start their own businesses or side hustles--which you can do in just a few hours--for a variety of reasons. Some want to be their own boss. Others want to make their living by doing something they love. Others seek the opportunity to make a bigger difference in the lives of others.

And some want to get rich--and they realize it's incredibly hard to get rich if you work for someone else. (Of course, there's nothing wrong with wanting to get rich.)

If that's you--if your goal is to become, say, a millionaire--one way to get there is to adopt some of the habits of people who have been there, done that, and have the bank accounts to show for it.

That's why Tom Corley surveyed over 177 self-made millionaires to understand their daily habits when he wrote the book Change Your Habits, Change Your Life

What habits do wealthy people have in common?

  • They surround themselves with successful people.
  • They waste as little time as possible.
  • They carve out a few minutes every day for focused thinking.
  • They read a lot.
  • They get plenty of sleep.

And 76 percent of them exercise at least 30 minutes a day. (One way they find the time to exercise is by--you guessed it--getting up well before their actual workday begins.)

Granted, exercise alone won't make you rich. And while there is a definite link, exercise and success may simply be correlated and not causal.

But then again... 

Many entrepreneurs believe health and fitness play a major role in their success. And with good reason. Research shows:

Owning your own business means making hundreds of small and large decisions...working long hours...inspiring, motivating, and setting a good example for a team...dealing with constant stress....

That's why health and fitness matter and can make a huge difference. Exercise makes you smarter, gives you more energy, puts you in a better mood, and helps you better deal with anxiety and stress.

And that's why Tony Robbins follows a strict diet and exercise plan. So does seven-time Nascar champ Jimmie Johnson. And Def Leppard guitarist Phil Collen. And ex-Twitter CEO Dick Costolo.

Plus, while the physical and cognitive benefits are clear, the emotional benefits of exercise--like perseverance, resilience, determination, and mental toughness, all of which successful entrepreneurs possess--are just as important.

If you feel stuck in your career or your business, if you have big dreams but don't feel like you're making any progress, adopt the exercise habit countless successful entrepreneurs--and many self-made millionaires--embrace.

And self-made billionaires. Richard Branson says working out boosts his productivity. "I can achieve twice as much in a day by keeping fit," he says.

So if you want to get rich--and even if you don't--make exercise a part of your daily routine.

You'll improve your body. You'll improve your mind. You'll build more of the determination and grit you need to stay the course when others give up.

And don't say you don't have the time. Do what over half of the self-made millionaires Corley surveyed do. Get up a little earlier and exercise first thing. (Which lets you gain a further advantage: Research shows that 20 minutes of moderate exercise improved participants' mood for up to 12 hours--so if you exercise early in the morning, you reap the mood benefit all day.)

Or eat at your desk while you work and turn lunch breaks into exercise time. 

If a guy like Sir Richard believes in the power of exercise, and can find the time to make exercise a part of his daily routine...then the rest of us definitely can.

And should.