Your face is a resident to 50 muscles and 20 of them are expression muscles. The sole purpose of these muscles is to assist in expressing emotions. In order for those muscles to hold the face firm you need to use them. If you can't laugh right now, I understand, but you can probably watch a comedy and brighten your mood instead of news alerts about the coronavirus. According to science, the act of laughing or a simple smile can trigger a release of a happy chemicals which can instantly improve the mood. As a result you may appear more radiant and more approachable.