How many times have you heard a client tell you that they just don’t have the willpower to stick with their goals? Or perhaps you’ve told clients that they just need to exert more willpower. But what, exactly, is willpower? Does it even exist? And if it does, are you just born with it, or is it a learned thing? Or is it like a muscle and you have to build it up over time?

As always, we turn to the research—and a few experts—to answer tough questions like these. Read on to learn more about willpower and what it can and can’t do when it comes to sticking with healthy habits and working toward big and small goals.

A Brief History of Willpower

In his 2013 paper published in Theory and Psychology, Robert Kugelmann, PhD, a psychology professor at the University of Dallas, explains that prior to the mid-nineteenth century, the term “willpower” did not exist. When it first started appearing in books and articles in the 1830s, it was presented in terms of “power of the will” and was aligned with endurance, self-control and resolve.

According to Dr. Kugelmann, the idea of “willpower” probably came and took shape from a number of sources, including “philosophical treatises, self-help books, phrenology, mesmerism and spiritualism.” By the late 1800s, willpower was commonly used to describe a character trait. Since then, it has had several overlapping meanings, including self-control, testing the limits of endurance, and resoluteness and effort.

Around 1922, however, the idea of willpower was overthrown by modern psychology when, in an article in The New York Times, Silas Bent, an editor for the paper, declared, “The newer psychology appeals to what it regards as a higher authority [than the will], the subliminal self, shrouded in the subconscious mind. Suggestion has superseded command, and effortless imagination is thus recognized as the source of health, right conduct, and reform…King Will has been dethroned.”

Of course, as Dr. Kugelmann points out, willpower didn’t just disappear. It simply became enshrouded in newer terminology for what was essentially the same thing, such as motivation, empowerment and assertiveness. And while the idea of willpower never really ceased to exist, willpower itself really began to make a big comeback in the twenty-first century

What is Willpower?

The word willpower can have both good and bad connotations. For example, when someone exerts their will to succeed at something, we applaud their success and ability to persevere—their willpower. On the other hand, when someone seems to lack willpower, it’s used as a reason or excuse for failing to meet a goal.

But what exactly is willpower? “Willpower is the mental ability to resist temptation and remain focused on a task or goal,” says Patricia A. Farrell, PhD, a licensed clinical psychologist based in both New Jersey and Florida, and author of several books. “It is often described as the ability to control one’s thoughts, emotions and actions, especially in difficult or frustrating situations.” She adds that willpower is not all-or-nothing, nor is it unlimited. “Willpower is a limited resource, meaning that it can be depleted, but it can also be strengthened.”

In his book, Willpower: Rediscovering the Greatest Human Strength, Roy Baumeister, PhD, along with co-author and journalist, John Tierney, uses an example from their study lab to illustrate the limited nature of willpower. Half of the students in the study were invited to eat freshly baked chocolate chip cookies, while the other half were asked to resist the cookies and instead snack on radishes. The students were then given impossible geometry puzzles to solve. The students who ate the cookies worked on the puzzles, on average, for 20 minutes. The students who were stuck with the radishes gave up after an average of eight minutes.

Based on this and other similar studies, Dr. Baumeister and other researchers began forming theories that suggested that willpower becomes depleted during various acts of self-control—and that the same energy that is used for self-control is also used for decision-making.

In practical terms, this means that people tend to make poorer decisions after having to exert a great deal of willpower. It also works in reverse—people tend to have lower levels of self-control after having to make decisions.

Farrell describes this as decision fatigue, “where you make too many decisions in one day that can drain your willpower.” Does this sound familiar? Think of the client who, having been “good” all day, comes home from work and can’t resist the siren call of dessert or other foods they had planned to avoid. While resisting a donut in the breakroom at work may seem easy, a long day of decision-making can make it nearly impossible to say no to cake after dinner.

Here's a non-food example: You might have plenty of patience to calmly deal with a challenging coworker at the beginning of the workday, but by the end of the day, you find yourself losing your temper with them.

Want to learn more about willpower? Dive into these books.

Willpower: Rediscovering the Greatest Human Strength by Roy F. Baumeister and John Tierney

The Willpower Instinct: How Self-Control Works, Why It Matters, and What You Can Do to Get More of It by Kelly McGonigal, PhD

Willpower at Work

We often equate willpower with the occasional resistance to temptation, but we exercise willpower far more often than we might realize. In fact, according to Dr. Baumeister, research suggests that the average person spends three to four hours a day trying to resist temptation. And that’s just part of the willpower equation.

We use self-control, a derivative of willpower, throughout the day to control our thoughts, emotions, decision-making and task performance regulation. And while we might think of willpower as having to do solely with the mind, Baumeister and one of his students stumbled across a somewhat surprising finding: Glucose plays a role in self-control.

According to Dr. Baumeister, acts of self-control use glucose and, therefore, reduce glucose levels. In their studies, low glucose levels predicted poor performance on self-control tasks and tests.

Anyone who has felt themselves get “hangry” (i.e., hungry and angry) can relate, as this state may prompt one to eat whatever is available—and be more irritable until glucose levels rise. So, it’s not exactly surprising that Baumeister also found that replenishing glucose levels restores self-control.

Ways To Boost Self-control

Aside from glucose levels, there are other ways to boost self-control. Dr. Baumeister states that research suggests that consistently practicing self-control “exercises” over a couple of weeks can help improve self-control.

For example, he suggests using your non-dominant hand for activities like brushing your teeth or opening doors, consciously trying to maintain good posture throughout the day, or keeping a daily food diary.

Dr. Farrell offers additional tips for maximizing willpower and self-control, which you can offer your clients or apply to your own life. For example, she recommends practicing mindfulness, “because it provides a sense of self and awareness of your thoughts, feelings and actions that can help you to become more aware of your own existing willpower and how to use it effectively. It’s a ‘time out’ where only one thing remains paramount and that’s your goal where you are focusing your willpower.”

She suggests taking breaks throughout the day “to help recharge your willpower and help you stay focused on your tasks,” and avoid having to make too many decisions in a single day, which can lead to decision fatigue and drain willpower. “Limit what you will do and the decisions you make each day. Sometimes easier said than done, but try it.”

It’s important to take small steps toward a goal “to develop a sense of accomplishment,” says Dr. Farrell. Record these small accomplishments in a journal to remind yourself how far you’ve come.

And finally, “Learn relaxation exercises and develop interests in something enjoyable, like a hobby,” suggests Dr. Farrell. “Hobbies can be lifesavers in terms of emotional release and without expectations from others. You are engaged in the hobby for the sheer pleasure it provides.”

Of course, you may encounter clients who claim to simply have no willpower at all. For these clients, a different tactic may be needed. Instead of focusing on the idea of willpower, ask your client, “What are you willing to do right now? What one small step are you willing to take?” This approach places them more directly in the driver’s seat with an intentional decision (just make sure their glucose levels are replenished!).

Willpower is likely to continue to be a topic of much debate, both in and out of the psychological community, as not all researchers agree on the topic. That said, self-control is unquestionably an important skill for many things in life, and research shows that it can be strengthened. Perhaps not surprisingly, a 2017 study in the Journal of Personality found that people with more self-control tend to be happier, offering one more reason why it’s a skill worth practicing.