Why do some people have no problem getting up early every morning to hit the gym, while others can barely drag themselves there?

It has to do with our mind’s eye, according to social psychologist Emily Balcetis, who spoke at the New York TED conference last fall.

People who are out of shape and unmotivated to exercise perceive exercise very differently than people who are in shape and are motivated, Balcetis said. In a study where participants were asked to stand at a starting line and guess how far it is to the finish line, the fit/motivated people guessed the distance to be shorter than the out of shape/unmotivated.

But can you change your mind’s eye perception of exercise? Balcetis says yes. Watch her talk below to see how.