Success is great, but it's not the same thing as thriving.

Your business (and bank account) can be growing impressively, earning you all the outward signs of success and the esteem of fellow entrepreneurs, and yet it's totally possible that you're haunted by the sense that your life isn't all it could be. You're surviving--even succeeding--but you're not quite thriving.

It's a nagging worry that hits people at all levels of their careers, even those who appear to be at the very apex of achievement, such as über-successful Huffington Post founder Arianna Huffington. Seven years ago, she explained recently in an interview with Knowledge@Wharton, she was doing exceptionally well by all outward measures, but inwardly, big trouble was brewing.

"I collapsed from exhaustion, burnout, and sleep deprivation. I broke my cheekbone on the way down and got four stitches on my right eye," she tells her interviewer, Wharton Professor Adam Grant. "It started me on this journey of asking myself the big questions that we stop asking ourselves when we leave college: 'What is a good life? What is success?'"

The result was both her new book, Thrive: The Third Metric, the realization that our definition of success was often impoverished. It includes money and power but not well-being, wisdom, joy, and our capacity for empathy and wonder. Without these, "life is really reduced to our to-do list," she concluded.

How to thrive, not just succeed, raises big, meaty, philosophical questions, but as Huffington tells Grant, her approach to rebuilding her life with an expanded definition of success actually started with small changes. She outlined three modest alterations to her lifestyle that helped her not just look successful but feel successful, too.

An Extra Half-Hour

We've all read article after article about exactly how awful sleep deprivation is for your mental and physical health, but for many busy business owners that knowledge doesn't translate to actually getting the recommended amount of rest. Huffington was one of those underslept and overworked, at least until her collapse. Then she made a series of small modifications to her sleep schedule that eventually added up to a profound improvement.

"I began getting 30 minutes more sleep a night than I was getting before, until gradually I got from four to five hours, which is what I was getting before I collapsed, to seven to eight hours, which is what I'm getting now. The result has been transformational," she tells Grant, adding that "all the science now demonstrates unequivocally that when we get enough sleep, everything is better: our health; our mental capacity and clarity; our joy at life, and our ability to live life without reacting to every bad thing that happens."

Work On Your Body and Your Mind

Getting healthier doesn't have to mean training for a triathlon or signing up for weeklong silent retreats, Huffington argues. Doing right by your body and mind is a matter of minutes a day--so, no excuses!

"I used to meditate on and off, ever since I was 13 years old. But I actually introduced a daily practice, which started [at] five minutes and is now at least half an hour. I got to half an hour, again, gradually by experiencing the rewards of those five minutes," she says. "[I also do] some form of movement--yoga, exercise--even when I'm traveling, in my hotel room, for just 10 minutes."

Make Space for Giving

For many of us, a meaningful life isn't about what we get or achieve; it's about what we give to others. Again, moving from surviving to thriving is largely a matter of putting that simple wisdom into practice, and the best way to do that, Huffington insists, is to start small.

"Giving in small daily ways has been really important. Leaving aside what we give to charity or volunteering time, just one of the first steps I recommend and I practice is to make personal connections with people who otherwise you might take for granted--the checkout clerk, the barista in the coffee shop, the cleaning crew," she advises, claiming even these small actions make a big difference.