It's not required, but depending on your other running gear, you might want to. Most men's running shorts include an inside liner that allows you to run without wearing underwear; it preserves your modesty and provides some support. If your shorts don't have a liner, you should probably wear anything below them. A T-shirt is all you need under your shirt if you don't have any kind of athletic supporter underneath it. A few women runners I know also wear a belt as part of their running attire. The belt includes a pouch that hangs down between the legs; this is where you put your female hygiene products. When you run, the movement of the belt against your skin helps keep you clean. Some women say they feel more comfortable running without underwear because there's less chance of an accident. Others claim it makes them feel more free and relaxed while running. The choice is up to you. If you'd like, you can buy a pair of Langots and use them as a replacement for your shoes while running. Or you may prefer not to waste money on something you're only going to use once or twice a year. There are several different types of footwear available for running including sneakers, boots, and sandals. Each type has its own advantages and disadvantages. Running in your sock feet is convenient but can be painful if you're not careful with your sizing. Socks tend to be too small which causes blisters.