I do my best work from about 6 to 10 every morning.

The neurons are firing at full-speed, the toasted bagel is providing some fuel for standing up all day at my desk. (That's right, I'm testing standing desks again, including one that has a treadmill and a Bluetooth connection.)

Late at night, I jump on to check email and browse through news feeds. I typically work about 40 hours in a week, but I tend to be a bit sporadic about when I'm at my desk. I cherish those early morning hours. I dive in at 4 p.m. and crank out some more work, feeling a burst of energy because I plan to log-off at 5 p.m. no matter what.

In the past, I've written about the incredible effort it takes to start a company and build up momentum. One of my favorite stories is about the entrepreneur who told me he did two or three power lunches per day to promote his startup. He must have had a massive expense account. I've been known to send off a hundred emails in a 15-minute span (none of them are spam) in a furious rapid-fire attempt to find sources or track down cool products. I know what it means to work incredibly hard.

I know it takes perseverance and dedication. Yet, a comment today from Marissa Mayer in an interview seemed so off base that I worry there's an app developer, public relations guru, or product design genius who will read what she said and decide to start working three times as hard, and end up in the hospital from fatigue.

She said, in the early days of Google, people would work as much as 130 hours in a week, including an all-nighter. She claims that was the recipe for success, but the recipe is seriously flawed. Scientists have proved her wrong. Working more hours is not effective. Working smarter, taking breaks, choosing when you work, and leading a team more effectively will produce better results in the long run.

There's a reason working smarter is more effective. From my experience, whatever I'm producing at 3 a.m. is garbage anyway. In a short span--say that 6 to 10 a.m. window--I'm producing better work than anything I'd do in the late evening. You might think this depends on the job you're doing, but it's all about the science. We have a limited capacity for processing information. We have a few "circuits" and some adrenaline to help push ourselves, but it won't last long. In fact, science has found that you can blow out your adrenal glands pretty easily. (There's even a name for that--it's called adrenal gland dysfunction.) It's not possible to work 130 hours per week and still sleep soundly. There are only 120 hours in a five-day period!

Worse than this, Mayer even suggested that employees planned out their eating and bathroom breaks in order to work that much. The whole point here is that the argument is wrong. Working 130 hours does not lead to success. Working smarter leads to success. Also, perseverance is not the same as long hours. Perseverance is refusing to take no for an answer. It is not a timeframe. It is never giving up on an idea. It is leading with so much conviction and purpose that success eventually finds you rather than the other way around. It's about availability, dedication, and integrity, not about all-nighters. It sends a mixed message to people running a company that all you have to do is check email at 3 a.m. to make everyone love your widget. I'd say it's the opposite. You have to figure out how to work smart enough during the prime working hours and avoid checking email at 3 a.m. at all costs, because that practice can lead to outright failure and fatigue. It's unhealthy and unwise. It leads to health problems, a lack of balance in work and life, and even depression.

A better plan: Make a better widget. Sometimes, working longer hours and producing a worse product is the one thing that prevents people from succeeding.

And about my 40 hours: I'm trying to figure out how to work less and make each hour count for more than it has in the past. I'd rather spend my free time reading books. We all get 24 hours in a day, which levels the playing field. It's not how many hours we burn up working; it's how many hours we don't burn up.