We often blame our bad habits and poor decisions on a lack of willpower. You meant to go to the gym, but you stayed on the couch. You planned to cook a healthy dinner, but fast food won again. It’s easy to think we just aren’t strong enough mentally. But what if willpower doesn’t quite work the way we assume?

New insights from behavioral psychology suggest that willpower is not a fixed character trait, but more like a muscle—it tires with use. By understanding how decision-making affects willpower, and how to structure our days more intelligently, we can take back control and start making better, more consistent choices.

Decision Fatigue in the Courtroom

A landmark study published by the National Academy of Sciences explored over 1,100 parole rulings made by judges. You might expect that each case would be decided on the merits of the crime or the prisoner’s behavior. Instead, the biggest factor wasn’t legal—it was timing.

Early in the day, judges granted parole about 65% of the time. As the morning wore on and more decisions were made, favorable rulings dropped dramatically—sometimes to nearly 0%. But after a lunch break, favorable rulings jumped back up to 65%, then declined again by the end of the day.

The findings were startling: when judges were mentally fresh, they made thoughtful, case-by-case rulings. But as mental fatigue set in, they were more likely to take the “easy” route and deny parole, regardless of the actual merits of the case.

This is a textbook example of what researchers call decision fatigue. The more decisions you make, the more your mental energy declines, and the more likely you are to fall back on default choices—or make none at all.

Your Daily Life Is Full of Similar Traps

You don’t have to be a judge to experience decision fatigue. Think about your own days. After a string of meetings, emails, and errands, how do you feel when it’s time to cook dinner or exercise? If you’ve spent the whole day making decisions—big or small—your willpower has likely been depleted. That’s when bad habits creep in: skipping workouts, snapping at loved ones, or mindlessly scrolling your phone.

But there’s good news. Just like muscle strength, your ability to manage willpower can improve with the right approach. Here are five strategies to keep decision fatigue at bay and help you make better choices—even when your energy is low.

1. Decide Once, Not Ten Times: Plan Ahead

Repeated daily choices—what to wear, what to eat, when to run errands—add up quickly. Every time you deliberate over a small decision, you’re spending mental energy that could be better saved for bigger things.

The solution? Plan your repeatable tasks the night before. Choose tomorrow’s outfit, set out your gym gear, and prep meals ahead of time. By eliminating needless decisions, you preserve your mental reserves for things that truly matter.

2. Do What Matters Most, First

Your brain is sharpest early in the day, before it’s bogged down by distractions and fatigue. If something really matters to you—whether it’s writing a book, launching a business, or simply eating better—put it at the top of your to-do list.

Don’t wait until the evening to do your most important work. That’s when you’re most vulnerable to procrastination. Protect your morning, and let your highest energy levels work in your favor.

3. Replace Daily Choices with Commitments

Relying on willpower to make the right decision every day is risky. Instead of deciding if you’ll go to the gym, schedule it. Make it part of your identity and your routine.

For example, rather than thinking, “I hope I’ll find time to write today,” say, “I write every Monday and Thursday at 8 a.m.” This removes the mental debate entirely. It’s not a decision anymore—it’s a commitment.

4. Fuel Your Brain: Eat Before Big Decisions

The judge study revealed that something as simple as a food break improved the quality of decisions. That’s because willpower is affected by glucose levels—your brain’s primary energy source.

So if you know you’ve got important decisions to make later in the day, have a nourishing meal or snack beforehand. A mix of protein and complex carbs can do wonders to restore your mental sharpness.

5. Simplify Your Environment

Decision fatigue often creeps in when our lives are cluttered—with choices, distractions, and unnecessary tasks. Simplify wherever you can. Cut out activities that don’t serve your goals. Reduce options when possible (fewer outfits to choose from, fewer apps on your phone, fewer obligations in your calendar).

Every simplified aspect of your life is one less drain on your willpower—and one more opportunity to stay focused on what truly matters.

Final Thoughts: Willpower Is Renewable

Willpower isn’t something you either have or don’t have. It’s fluid. It rises and falls throughout the day, and it’s heavily influenced by your routines, your environment, and the demands placed on your mind.

By making smarter structural choices—scheduling commitments, planning ahead, simplifying decisions, and aligning your most important tasks with your highest energy—you can preserve willpower for the moments it counts.

In the end, mastering willpower isn’t about being stronger. It’s about being smarter.