If you want to strengthen your self-control or any of the executive skills mentioned in previous blogs, you will have to pace yourself. Too much exertion, fatigue and information overload tend to weaken the executive skills and leaves you more susceptible to distractions.

Even practising self-control itself, such as turning down that second piece of cake, uses up energy. Studies show that people who exert themselves mentally, such as resisting the temptation to eat chocolate, gave up on problems sooner when presented with them immediately afterwards.

This holds true for both physical and mental exertion. One classic example of how continually making decisions impacts energy depletion and performance was the study of a parole board’s decisions. An article in the New York Times describes the results of this energy drain. After examining more than 1100 decisions over the course of a year, it was found that prisoners who appeared before the board early in the morning received parole 70% of the time; but those who appeared late in the day were paroled less than 10% of the time. In at least one incidence two prisoners were serving the same sentence for identical crimes and yet the one appearing at 8:50 a.m. was paroled while the one appearing at 3:30 p.m. was denied.

Ruling on case after case throughout the day caused decision fatigue and warped their judgment. And it can have a similar effect on all of us if we do not manage our energy as well as our time.

Managing energy presumes you are building enough energy in the first place – through such things as adequate sleep, exercise and proper nutrition. Probably the biggest reason for an inadequate supply of energy is due to a lack of sleep. Sleep has taken the brunt of our need for additional time to do all the things we want to do – to the point where the average recommended sleep time of 7 to 8 hours a night is being short-changed by at least an hour.

As explained by Wray Herbert, in his book, On second thought, if we are overtired and mentally depleted, our brain switches automatically to its less effortless mode; it’s just too difficult to crunch a lot of information and sort it intelligently if we lack the fuel for thinking. If you’re in the habit of composing email and carrying on a conversation with a co-worker while eating lunch, for instance, you could be creating a brain drain.

David Rock, in his book, Your brain at work, claims that the prefrontal cortex, the part of the brain responsible for thinking things through and making decisions, uses up metabolic fuel faster than people realize, and that we have a limited amount of energy resources for activities such as decision-making and self-control. Making one difficult decision makes the next one more difficult.

If you want more detailed information on managing your energy, refer to my e-Book, “Manage your personal energy: Increase performance while retaining your health,” at Bookboon.com.

Starting in the morning we tend to get sleepy every 90 minutes. These 90 minute cycles are ultradian rhythms, which determine when we feel alert and productive. We perform best during these 90 minute cycles, with about a 20 minute “sleepy zone” in between.

If you force yourself to work on tasks requiring high energy after the 90 minutes, your performance suffers and you get a low return on your invested time. It makes sense that when you are concentrating on the same task for a long time, your brain needs a break. But a change in pace is relaxing, and doing low-energy work like checking e-mail is usually okay.

Sleep helps the brain and body to recuperate after a hard day at the office, and since most people seem to be getting insufficient sleep, daytime napping will help boost alertness, mood and cognitive functioning. A 20 minute nap appears to be the best, and naps of an hour or more are not recommended. The best time is thought to be between 2 PM and 4 PM since it is usually easier to fall asleep at this time.

Most companies would never consider allowing a nap break to replace the normal coffee break; but if you are an entrepreneur, you are in control. Otherwise, simply closing your eyes for 10 minutes while holding your coffee cup still helps.

Pacing yourself, conserving energy and getting adequate sleep are three ways to strengthen your self-control and other executive skills. The next blog article will include more.