Chapped lips aren’t the only thing to worry about this winter. It may seem like weird science, but a five-year study has found that for people who have high blood pressure, the winter months are the time when it can become harder to control.

The study, which focused on military veterans with hypertension, found that about sixty percent of patients displayed a noticeable change in blood pressure management during the winter. In addition, patients treated in the summer months returned to normal blood pressure levels more readily than those who were treated during the winter.

Regardless of where the subjects lived, researchers found these seasonal variations existed. So what’s to blame? Well, maybe it’s more who’s to blame. Although researchers aren’t sure exactly what is causing this to happen, they believe these blood pressure changes could be caused by reduced exercise and an altered diet when the days are shorter and the weather is colder, factors that can lead to general weight gain. The American Heart Association says that seasonal variations also exist for heart attacks and strokes. Just like rising blood pressure, these maladies are often more common during the winter.

We all know it’s not as easy to exercise outside when the weather turns chillier… and it’s certainly difficult to turn down that slice of pumpkin pie… but you may want to think twice before skipping out on your morning walk or run this winter. It may benefit you more than you realize.