Wool is great for socks and workout clothes for a ton of reasons, including because it's warm even when wet. As a bonus, you can wear wool for multiple workouts without stinking it up. But it turns out the reason isn't what you think: Wool doesn't kill bacteria, it just hides their odour.
Photo by johnrp.
Lanolin, an oily substance sheep make from glands in their skin, does have antibacterial properties. But by the time the wool is washed and treated to make those dreamy soft (and tragically expensive) hiking and running clothes, the lanolin is long gone. Instead, the fibres seem to be trapping the stinky chemicals that sweat-eating bacteria excrete.
That means that your gear will start to stink eventually, so frequent washing is still important. Read more myths about wool and other performance fabrics at the link below, including tips on keeping your waterproof layers waterproof longer.
7 Performance Fabric Myths Everyone Believes [Bicycling]