The key to Billionaire success…  physical fitness. Here’s what each of them have to say.

Richard Branson | Founder, Virgin Group

Branson, worth a reported $5 billion, said his physical activities, which can include swimming, Bikram Yoga, rock climbing, running, and weight lifting, give him at least four additional hours of productivity each day.

“I definitely can achieve twice as much by keeping fit,” Branson has said in the past. “It keeps the brain functioning well.”

Mark Zuckerberg | CEO, Facebook

“I make sure I work out at least three times a week — usually first thing when I wake up.”

Mark Cuban | Owner, Dallas Mavericks

He always tries to get in an hour of cardio each day. In his words, exercising helps fuel his competitive spirit, a trait he transfers over to his business dealings.

Warren Buffett | Chairman, Berkshire Hathaway

Even at 87, the world’s greatest investor still finds time to work out.

Brian Chesky | CEO, Airbnb

Airbnb chief Brian Chesky, a former competitive bodybuilder, stays diesel with a weight-rich workout regiment!

Jeff Bezos | CEO, Amazon

Bezos works out with strength training regularly and insists (unlike many billionaires) on eight hours of sleep a night.

Vince McMahon | CEO, WWE

In case you didn’t know, the WWE head honcho is over 70. Despite basically micromanaging a billion-dollar global franchise — with just three-to-four hours of sleep per night and an inhumane work ethic — the now 72-year-old still gets it in at the gym.