Currently, there is no scientific evidence that fitness trackers are not safe to wear, according to John Sweetenham, MD, a hematologist at the University of Utah’s Huntsman Cancer Institute. Furthermore, the Center for Disease Control and Prevention's experts added no scientific evidence confirming whether radiofrequency (RF) radiation from cell phones can cause health issues years later. Fitness trackers appear to be safe to use regularly; however, like anything in life, moderation is required.