Researchers at the University of New Hampshire had more than 200 people complete two surveys. The first one included questions on a wide range of activities including exercise, and finished by asking half of the participants to describe a positive or negative experience that might increase their motivation to exercise. Eight days later, they filled out a second questionnaire that asked about their exercise sessions in the intervening week. The results: people who drew on a previous, concrete mental image of how good it feels to exercise were much more likely to be active than those who didn’t tap into a feel-good fitness moment. The participants who drew on a negative motivating exercise experience (like that time they didn’t make the soccer team) were more likely to be active than the group who didn’t recall any fitness memory, but not as likely to work out than those who thought positively. “While it seems that some people are motivated to work harder by thinking back on a bad or uncomfortable moment that they never want to relive, most of us tend to do better with positive reinforcement,” says psychologist and study coauthor David Pillemer. “We believe it works by reminding you of the positive emotions associated with exercise. It may also increase your feelings of competence and inspire you to exercise in the future.” For more fitness motivation, check out these 31 ways to never skip another workout.