Many people think willpower works like a battery: It starts each day fully charged and drains as life throws challenges your way. The more fatigued you get, the harder it becomes to stay disciplined.

Psychologists call this ego depletion, and it’s a common excuse for skipping workouts, cheating on a diet, or avoiding tough tasks after a demanding day.

But does hard work really erode discipline, or is it more a matter of mindset?

Scientists at Stanford University put this question to the test. First, they asked 66 people to rate statements like:

  • “After a mentally strenuous activity, you must rest to recharge your energy.”
  • “Your mental stamina fuels itself; even after tough tasks, you can keep going.”

The researchers labelled people who agreed more with the first as having a “limited” view of willpower, while those who sided with the second had a “non-limited” view.

Next, everyone completed two 5-minute tasks. The first was simple—crossing out every “e” on a page of text. The second was split: half repeated the same task, while the other half tackled a more complex version that required deeper focus.

Afterward, all participants took the Stroop test, a psychological test that measures focus and thinking speed.

The results showed that those with a limited view of willpower performed worse on the Stroop test after the mentally demanding task, making more mistakes and showing signs of fatigue. Meanwhile, those with a non-limited mindset showed no dip in focus or performance, even after the tougher challenge.

In other words, how people thought about willpower shaped how they performed. If they believed hard work drained their energy, their ability to concentrate dropped. But if they saw hard work as energizing, their willpower stayed strong:

 How Mindset Affects Willpower

These findings weren’t a one-off, either.

Follow-up studies showed that people with a non-limited mindset procrastinated less, ate less junk food, and stuck to their goals more often than those with a limited mindset.

This effect extends to health and fitness, too. 

For instance, in a study by the University of Toronto, researchers tracked 322 people for 3 weeks. Those with a non-limited mindset were more likely to work out and less likely to snack after tough days than their limited-mindset peers.

Here’s the good news: changing your mindset is simple.

Research shows that simply learning how belief affects behavior can nudge you toward a non-limited perspective.

So, the next time you feel worn out, remind yourself: hard work can invigorate rather than exhaust you. 

Adopting this mindset can help you skip fewer workouts, stay on track with your diet, or finish your day without feeling wiped out.

Scientific References +