Smartwatches and smart rings are "wellness" devices. They may have some FDA-approved sensors, but there's always fine print saying to take worrying readings with a grain of salt. But smartwatch and smart ring makers are aiming for medical-grade accuracy at all costs (literally). Not necessarily for your peace of mind, but because there's profit to be had if the healthcare industry buys in. Sunday Runday (Image credit: Android Central) In this weekly column, Android Central Wearables Editor Michael Hicks talks about the world of wearables, apps, and fitness tech related to running and health, in his quest to get faster...