Willpower is the capacity to overrule the unconscious desires of the body in order to make rational decisions, like choosing a paleo-compliant avocado over a slice of pizza.  No matter what your goal is (50 flags, 315 on the bench, 50 approaches a month, etc.) you’re going to need it. Willpower: Rediscovering Humanity’s Greatest Strength is a definitive, easy to read book that will bring you up to speed on the latest psychology of willpower.  Willpower operates like a kind of mental gasoline.  Making conscious decisions uses it up, and it doesn’t recharge fully until you get a good night’s rest.  Here are nine facts about willpower:

1. Monitoring progress improves willpower

Showing someone with poor financial self-control his Visa bill before he makes a purchase activates a region in his brain which is active in people who are successful at managing their finances, and quiet in those who cannot.  People who use Mint.com tend to spend less money than people who don’t.

2.  Glucose matters

Making decisions takes glucose.  The brain is the principal energy consumer in the body.  The ability to resist temptation is closely tied to glucose levels in the bloodstream.  In a state of low glucose, willpower energy becomes depleted.  This causes people to revert to the easiest option on a menu of possible choices: the status quo.

In an experiment with the Israeli equivalent of a parole board, the chances of the board granting parole to an inmate prior to lunch approached 20%.  After lunch, it approached 65%.  Keeping a prisoner in jail is the status quo, the easy decision in this example because it frees the board from considering the ramifications of freeing a potentially still-criminal individual into the general population.

3. The body sends warning signs when you’re about to make bad decisions

Willpower depletion can be tricky to self-diagnose, but there are signs: feeling emotions more strongly than usual, difficulty making up one’s mind, unusual laziness.  Decisions made in this state are almost always suboptimal.

4.  Postpone gratification

It can be nigh on impossible to resist temptation head on, but studies show that coming at it obliquely does help augment willpower.  When you’re at the squat rack, and your body is ready to give up, tell yourself you’ll go easier on the next lift.  Your feeling of accomplishment from a successful lift may just get you through all the others.

5.  Disorganization destroys willpower

When the brain has an unfinished task, the task occupies mental energy.  When there are a sufficient number of unfinished tasks (most professionals average 150 items on their to-do lists) mental energy is fragmented across these small jobs.  At that point, making strides on any of them becomes very difficult.  Developing an orderly, specific system for completing tasks is crucial.

6.  Making decisions tires out your brain

Making decisions with large numbers of options is willpower depleting. People who are depleted often show an irrational desire not to give up options.  This may explain some of the behavior of women who delay marriage.  In cities and towns where the dating pool is enormous, the possibility that she may settle for a lesser male increases.  So she avoids making the decision entirely, to her own detriment.  This may also have some relevance to game.  Being at a bar with a large number of other men (even if there is a comparable or greater number of women) probably impedes notch acquisition.

7.  Looking at porn is bad for discipline in other areas

Hot women change neurological activity in men’s brains.  “Men who saw photos of hot women shifted toward getting an immediate reward instead of waiting for a larger payoff in the future. Apparently, the sight of an attractive woman makes men want cash right away.”  Looking at porn destroys willpower.

8.  Seeing your reflection enhances willpower

“Whenever people focused on themselves, they seemed to compare what they saw with some sort of idea of what they should be like.”  Putting a mirror on the desk, or in the kitchen, helps remind the mind of you of your self-ideal, and stop behavior that might hold back your goals.  It’s a cheap and easy reality check.

9.  Your friends can be major willpower assets

Making a commitment to a friend (referee) strengthens willpower.  So do financial penalties.  A website called stickk.com allows users to pick any goal they want and choose a penalty when they fail to reach it.  Penalties can include things like a donation to a cause a user hates or shame emails sent to family members.  “People who draw up a contract without a financial penalty or a referee succeed only 35 percent of the time, whereas the ones with a penalty and a referee succeed nearly 80 percent of the time.”

 Read More: How To Change Your Bad Habits