With very few exceptions, yes. Professional runners log hundreds of miles in training, and keeping their feet healthy during such heavy training loads is essential.
Socks help prevent blisters, which take time to heal. They cause discomfort that can alter a runner’s stride, which can cause injury over time. Blisters, while inevitable, should be limited as much as possible, and wearing socks goes a long way in doing so.
Also, many professional runners use compression socks to minimize fatigue during runs and races, as well as a way to speed up recovery between workouts.
We know of one exception to this rule. One of our writers knows a professional runner who chooses to train without socks, but races with them on. He does so purposefully to cause blisters and over time, build up calluses and, in his words, “to toughen up my feet.”
In addition to running, he’s also a professional hunter, often spending days in the woods. His purpose in building bulletproof feet is to prepare them during training for anything that may occur during his hunts. This is an extreme method of training — one that we don’t recommend — but it’s worth noting.