Endless ink (and pixel space) has been spent discussing the challenges of work-life balance for founders. But entrepreneur and former Facebook director of market development (and Mark Zuckerberg sibling) Randi Zuckerberg managed to convey the challenges and tradeoffs of the entrepreneurial lifestyle in a rather more concise fashion on Twitter a few years back:

Want to see your kids, keep fit, and keep your business going? Forget sleep, according to this formula. And you won't be spending much time with your friends, either. As Zuckerberg explains in this short interview, for her, fitness and friends often fall by the wayside, a sad reality but one she's willing to level with the world about.

Some founders agree.

This sounds harsh, but it's true, according to a recent interview with Storenvy founder Jon Crawford on Founder Dating. "Work, sleep, family, fitness, or friends--pick three. It's true. In order to kick ass and do big things, I think you have to be imbalanced. I'm sure there are exceptions, but every person I've seen riding on a rocket ship was imbalanced while that rocket ship was being built. You have to decide if you want it," Crawford declares.

"If you want to spend a lot of time with your friends and see all the Oscar-nominated movies and get good sleep at night and exercise, then it's going to be hard to give a start-up everything it needs. If you care about your startup more than you care about all those things, then go for it. But it comes with sacrifice," he says, leveling with would-be founders. Along similar lines, other entrepreneurs (or more often ex-entrepreneurs) have confessed that the start-up lifestyle and family life can be an impossible balance.

Is this true for you?

Zuckerberg's hard formula has the benefit of concision and clarity, and the endorsement of Crawford and others, but I'm curious, is it true for you? Several high-profile entrepreneurs, such as Basecamp co-founder and CTO David Heinemeier Hansson, have publicly declared that they can get all the work required for their start-up to succeed done in a moderate 40 hours a week, leaving, presumably, enough time for exercise, family, friends, and fitness (or at least more than two of those).

Are these apparently more balanced founders benefiting from special circumstances? Are they painting a slightly rosier than reality picture of their workloads and lifestyle for public consumption? What do you think?

Is Zuckerberg's formula too gloomy, or refreshingly honest?