Anytime we set a goal—and January is a prime time to do so—we start off with the best of intentions. But two weeks (or sometimes even two days) in, we tend to lose motivation. Going to the gym no longer seems so fun when running on the treadmill feels like we’re a hamster on a wheel. And as this video from asapSCIENCE explains, having fun and enjoying yourself (what researchers call “play”) is one of the key motivating factors to sticking with any goal. So if you want to exercise more, pick something you actually like to do!