Embodiments of wearable electronic devices, components thereof, and related systems and techniques are disclosed herein. For example, a wearable electronic device may include a wearable support structure having a first surface and a second surface; a first electrode located at the first surface, wherein, when the wearable electronic device is worn by a user on a portion of the user's body, the first electrode is arranged to contact the user's skin in the portion of the user's body; a second electrode located at the second surface, wherein, when the wearable electronic device is worn by a user on the portion of the user's body, the second electrode is arranged to not contact the user's skin in the portion of the user's body; and a resistance switch having first and second input terminals coupled to the first and second electrodes, respectively. Other embodiments may be disclosed and/or claimed.