Each day, the average adult makes 35,000 different decisions. A few decisions can be life-changing. Most are insignificant. Many decisions don't change your life in a moment, but over time can lead you far off the path you desire for your life.

For example:

Your alarm beeps at 5:30 am. Your bed is warm and the pillow is soft. It’s dark and quiet. One more hour of sleep would feel so good. Plus, sleep is good for you, right? You could get your workout in tomorrow instead. Do you go back to sleep, or get up and go to the gym?

You’ve showered and gotten ready for the day. It’s time for breakfast, before you head off to work. You know you’ll feel better later if you cook up some eggs and bacon, or make a low-carb protein shake. But, you can have a bowl of cereal ready in about 30 seconds instead of cooking for ten minutes. And the cereal is already out for the kids, anyway. It’s convenient and tastes pretty good too. What do you do?

You get to work, and one of your co-workers brought coffee and donuts for another co-worker’s birthday. It wasn’t part of the plan, but it’s free food, and it’s a “special occasion.” Do you eat the donuts, or just drink the coffee?

Situations like these situations play out everyday. Unless you have a full supply of willpower, you'll often choose the pleasures of the moment, and feel guilty later because you shortchanged your future.

I’d like to propose a different perspective on this age-old situation of "I know what to do. I just don't do it."

First, I need to set the stage with an understanding of willpower and decision fatigue.

Willpower and Decision Fatigue

Short-term comfort and pleasure is pretty tempting. In each of the examples above, you need a certain amount of willpower to ignore temptation.

Willpower: control exerted to do something or restrain impulses

Willpower is the mental energy needed to do what needs to be done, or to avoid what shouldn’t be done.

Because willpower requires mental effort and energy, you need a reserve of mental energy to exercise willpower. Decision-making is the biggest drain on that mental energy.

Roy Baumeister and John Tierney, in their book Willpower – Rediscovering the Greatest Human Strength, describe decision fatigue as “the deteriorating quality of decisions made by an individual after a long session of decision making.”

In essence, the more decisions you make, the less willpower you'll have. The more willpower you use, the more likely it is that you’ll make poor decisions.

Can you see why it's a bad idea to schedule an important meeting at the end of the workday, or why you should never make important marital or family decisions late at night?

As the day goes on, and you’re faced with family, work, financial, and fitness decisions, you make lower and lower-quality decisions.

An exhausting day at work, followed by a half hour trying to pick out the perfect outfit for dinner, will make it really hard to choose wisely from the restaurant menu.

Or, if you don't go out, just answering the question “What’s for dinner?” can be an overwhelming decision to answer. So you probably end up ordering pizza instead.

How to Conserve Your Willpower

Each day, you begin with a certain level of willpower. If you wake up tired from the day before, you won't have a fully recharged willpower battery. That doesn't mean you get a "hall pass" from good decision making. You are still responsible for every decision you make. You just need to conserve your willpower for decisions that are most important.

It’s like when your cell phone battery gets low and you don't have a charger handy. You use your phone for just the essentials. You might also turn off notifications, stop apps that run in the background, and turn down the screen brightness. You save your battery for only what's most important.

You can do the same thing with your willpower battery. To conserve willpower, you can: