What IP rating do I need for sweaty workouts?

IPX4 is the minimum for sweat resistance and covers most casual runners. IP55 (Shokz OpenFit 2+) handles dust plus sweat and rain. IP67 (Shokz OpenRun) means full submersion protection, useful if you run in heavy rain or want to rinse them off. For high-sweat users or hot-yoga crossovers, aim for IP67 or higher.