Founders still romanticize the idea that running on five hours of sleep is a signal of grind and grit. It isn’t. It’s one of the quietest and most reliable ways to sabotage your judgment, your creativity, and the long-term trajectory of your company.

There is a gap between what people think sleep deprivation does to performance and what it actually does. The science on this is not ambiguous. When you deprive your brain of adequate rest, you degrade nearly every function that matters for leading a high-growth business.

Researchers studying partial sleep deprivation have shown that even five consecutive short nights dramatically reduce the quality of decision-making. In one study, people gathered less data before choosing and took on more risk, even when the consequences were meaningful. Another review found that both total and partial sleep loss impair a person’s ability to make sound decisions under uncertainty, which is the exact environment founders operate in. Brain-imaging research shows that sleep-deprived individuals have dampened neural responses to both rewards and losses. In practice, this means poor risk assessment, inconsistent emotional reactions, and an inability to read situations with clarity.

These findings extend further. Cognitive studies consistently show slower reaction times, degraded memory, reduced attention, and less capacity to prioritize. When you think you’re performing fine on five hours, the research suggests you’re actually performing like someone operating below baseline without realizing it.

This is why the most experienced founders and operators have moved away from the hustle myth of minimal sleep. Arianna Huffington is probably the loudest voice, but she isn’t the only one. After collapsing from exhaustion while leading The Huffington Post, she rebuilt her operating system around seven to eight hours a night and has argued repeatedly that sleep is a long-term performance advantage. Others in the wellness-and-performance world have adopted the same stance: sleep is not a luxury. It’s cognitive infrastructure.

The logic is simple. The founder’s job is not to do the most tasks. It is to make the highest-leverage decisions with the greatest clarity and to maintain steady emotional regulation in the face of volatility. Those functions depend on sleep more than they depend on willpower.

Short nights create fake emergencies. They make everything feel urgent. They narrow your time horizon and reduce your ability to distinguish between noise and signal. When you sleep well, you can zoom out. You can prioritize. You can create space for insight. The best strategic ideas rarely come from a sleep-deprived brain.

If you’re regularly sleeping five hours and telling yourself it’s fine, that’s the biggest warning sign. Almost everyone who is chronically under-rested believes they’re the exception. Almost no one is.

One of the easiest competitive advantages available to founders is simply getting enough rest to think sharply. Your company runs on the quality of your decisions. Your decisions run on the quality of your mind. And your mind runs on the quality of your sleep.

How many hours are you actually sleeping—and what would change in your leadership if you added just one more hour a night?