Perhaps one of the most uncomfortable sensations you can feel while participating in athletic activities is chafing when running. Chafing can even lead to blisters, which can be quite painful. To stop chafing when running, you will first need to identify what is causing this unpleasant sensation. Friction between clothing and skin is the most common cause of chafing, so it is a good idea to start by taking stock of what you are wearing while running and whether such clothing is the best choice for running attire.
Loose, baggy clothing can lead to chafing when running because the materials from the clothing will have plenty of opportunity to move back and forth over your skin. This is especially common on the inner thighs, or even the underarms and nipples. To counteract chafing when running that is a result of clothing friction, try to wear a base layer that is tight-fitting and snug against the skin. This can help prevent excess movement that can lead to friction on certain parts of the body. Avoid abrasive materials, too; cotton can get wet, heavy, and abrasive, and when it rubs against the skin, chafing can occur.
Sweat can also enhance the likelihood that you will experience chafing when running. You can't, of course, stop yourself from sweating during physical activity, so again, your clothing choice can help prevent discomfort. Look for clothing made from synthetic materials that wick moisture away from the skin during physical activity. This will help ensure your skin stays relatively dry. Chafing is less likely to occur on dry skin than it is on wet skin, since the potential friction between clothing and skin is lower without moisture present. Avoid clothing with bulky seams that can dig into the skin or otherwise cause discomfort.
Your running motion may also lead to chafing while running, which can be a more difficult problem to solve. If you run with your arms close to your body, for example, you may be more likely to experience underarm chafing. Thighs rubbing together in a close gait can lead to chafing on the inner thighs, and chafing can occur on the heels of your feet as well. Correcting these problems can be an intensive task, and it is a good idea to visit a professional trainer who can do a gait analysis to help you come up with a more efficient and comfortable running stride.