I always thought working out is the perfect way to relive some stress. After all, what feels better when you’re tense than running your heart out or lifting a heavier set of weights. My motto has always been: workouts are the best when you can’t think about anything other than pain. But my motto might be wrong, unfortunately.

According to a new study published in psychoneuroendocrinology, people who are stressing out are more unlikely to make smart decisions while working out, or workout at all. Well, what does that mean, exactly?

The study says that the participants who had higher levels of cortisol (a hormone released by stress) had lower confidence levels while working out and were unable to make wise and competitive decisions. They say that the low confidence can affect a person’s behavior in both work and social settings.

Sean Fitzpatrick, an assistant professor in sport psychology at John F. Kennedy University, told Shape magazine:

Low confidence can often lead to avoidance. So, people who are worried about feeling like a failure might steer clear of the gym entirely. “If you go to the gym and are intimidated by the weight room,” says Dr. Fitzpatrick, “the only way to gain more confidence…is to actually lift the weights. A lack of confidence keeps many people from taking that first step, from pushing themselves, from trying something new.”

So next time you’re feeling stressed, know that exercise is a great way to try something new and to push a person’s limits. Remember, you got this! Enter that weight room.