Not long ago, Apple VP Alan Dye confessed, “I’m scared to death that at some point I’m going to get found out. You know, [Apple CEO] Tim Cook is going to realize the truth about me, which is I’m terrible.”

Sound familiar? If you’ve ever felt like a fraud, you’re not alone: Even the most successful people sometimes feel like they don’t deserve their success.

It’s called impostor syndrome, and it’s experienced as chronic self-doubt—a feeling that you haven’t earned your success. It affects people across a range of fields and from all walks of life. In fact, researchers believe that more than 70 percent of men and women have suffered from it at one point or another.

The good news: there’s a way out. Harvard Business School professor and social psychologist Amy Cuddy, author of the new book Presence, has conducted extensive research on the syndrome—and has experienced it herself.

In 2012, she gave a TED Talk on the topic, which went viral and has been watched over 34 million times. She talked about how body language affects how others see us, but also how it changes how we see ourselves. She believes that it’s possible to fake feelings of power until we truly feel more powerful. “Don’t fake it ‘til you make it. Fake it ‘til you become it,” she urged.

Here are three key takeaways from Cuddy’s work that you can implement today to become more confident—and more resilient—using body language.

Step One: Change your outlook in two minutes by changing your posture.
We can tell ourselves that we deserve success—but to really believe it, we need to feel it. Posture affects our body chemistry, thoughts, feelings, and physiology, Cuddy notes in her talk. When we feel powerful, we affect expansive, “high power” poses: we sit tall, we take up space, and we open up. When we feel powerless, we affect “low power” poses: we shrink and hunch over. Ask yourself: How are you sitting or standing? How are you presenting your power to the world—and to yourself?

Cuddy conducted research on people in high- and low-power poses. She proved that in just two minutes, these postures directly affect testosterone, a dominance hormone, and cortisol, a stress hormone. According to Cuddy’s research, high-power posers experience a rise in testosterone, making them more willing to take risks. Low-power posers, on the other hand, experience a rise in cortisol, making them more risk-averse. This means that your body can directly affect your mind—and fast. In Cuddy’s words, “Tiny tweaks can lead to big changes.”

Step Two: Notice the effect your body language has on others.
Just as these poses affect your own sense of well-being, they affect others’ perceptions of you—especially in high-stakes situations. Cuddy held mock job interviews where some interviewees had prepared in low-power positions and others had prepared in high-power positions. Evaluators reviewed the interviewees without knowing which group they belonged to. The high-power posers were more likely to get hired than the low-power posters—suggesting that when you believe in yourself, other people take notice and follow suit.

Step Three: Become the change you hope to see in yourself.
In her talk, Cuddy discussed a horrible car accident in which she suffered major head injuries. She was even told that she’d never complete college and that her IQ had dropped two deviations. For a long time, she felt like she was “faking it” whenever she succeeded. Years later, as a professor, she had a student at Harvard who felt the exact same way. The student was usually quiet in class and finally told Cuddy that she just didn’t belong. Cuddy urged her to fake it—to show up in class the next day and to act powerful, even if she didn’t feel strong inside. The next day, her student finally spoke up with an insightful comment—and her peers noticed. Months later, her student had changed, becoming more vocal and assertive. The lesson? It’s possible to boost self-confidence by simply acting self-confident, even when you don’t feel worthy within.

It’s normal to feel overwhelmed or undeserving from time to time. The key is to recognize when these moments are happening—and to get out of your own way.