Many leaders prolong their waking hours to get more done, but sleep-deprivation can significantly undermine the most important aspects of leadership, and negatively impact financial performance. Despite this, Harvard Business Review reports that 43% of business leaders do not get enough sleep at least four nights a week.

While most of the brain can function on relatively little sleep, the prefrontal cortex – where problem solving, reasoning, organizing, inhibition, and planning take place – cannot. The following functions of leadership have been proven to be negatively impacted by inadequate sleep, according to HBR.

1. Operating with a strong orientation to results.

In order to accomplish this, one must be able to focus, but also keep sight on the bigger picture to make sure your company is on track. Sleep deprivation weakens the ability to selectively focus attention. After 17 to 19 hours of wakefulness, performance is equal to that of a person with a blood alcohol level of 0.05%. In many countries that is the legal drinking limit. After around 20 hours of wakefulness, that number bumps up to 0.1%, which is the legal definition of drunk in the United States.

2. Solving problems effectively.

Sleep improves cognitive functioning, including creativity, pattern recognition, and insight. One study found that participants who had a good night’s sleep were twice as likely to discover a hidden shortcut in a task as those who didn’t sleep well.

3. Openness to outside perspectives.

Numerous studies have shown the impact sleep has on all three stages of learning: before learning, when the brain encodes new information; after learning, when it consolidates information; and before remembering, when the brain retrieves information from memory. In order to seek, translate, and merge different perspectives, the brain must be able to complete these processes. It’s critical for the brain to weigh the significance of different inputs, avoid tunnel vision, and reduce cognitive bias, which can’t happen in a sleep-deprived state.

4. Supporting others.

n order to help others you must understand their emotions and situations. However, when the brain is sleep deprived, you’re more likely to misinterpret facial cues or tone of voice, which can cause you to overreact to emotional events or express your feelings in a more negative manner. Additionally, employees feel less engaged with their work if their leaders are running on little sleep.

Develop training programs to increase awareness of the importance of sleep and encourage behavioral change regarding sleep habits. It’s also a good idea to make sure your policies regarding travel and expectations for email and response times are consistent with the value of sleep. Other measures to help workers get enough sleep are mandatory work-free vacations, time off, nap rooms, and smart technology.