Mark Zuckerberg, Richard Branson and Mark Cuban all agree that this one habit is key to success

Getty Images | Rick Friedman

Here's an easy but essential success tip you can steal from the billionaire's success playbook: exercise.

Working out is a habit the wealthy tend to have in common — 76 percent of the rich exercise for at least 30 minutes every day, according to Tom Corley, author of "Change Your Habits, Change Your Life."