Supportive and comfortable, a good pair of compression running shorts can improve the way you feel during and after a run, but the wrong pair may leave you feeling chafed and numb. The major purposes of compression shorts are to provide support in the thighs or groin, decrease chafing, and wick away sweat. The added muscular support may decrease muscle pain while running as well as decrease post-run recovery time. To find a pair of compression running shorts that offers all these benefits, you will need to choose shorts that provide the right amount of wicking and compression without cutting off circulation.
The fit is by far the most important factor when choosing compression running shorts. Shorts that are uncomfortably tight will reduce circulation to the legs, decreasing performance. A pair that is too loose, however, will not provide support or function any differently from other shorts.
You should also look for a pair that fits your body shape. While most compression running shorts are designed for men to provide extra support in the groin area, unisex and women's models are also available. Many women find that unisex shorts are still contoured too much for a man's body to fit comfortably on them, so they prefer a pair designed specifically with women in mind. Since compression shorts are designed to fit so close to the body, you should also pay attention to the location of seams as you try on a pair. Any seams that rub slightly in the dressing room are likely to chafe even on short runs, and may affect your stride on long runs as well.
The type of material used in compression running shorts will affect their performance. Any good compression clothing will be primarily synthetic to aid in wicking, but various materials may provide additional benefits. For example, certain varieties of polyester have been demonstrated to produce better wicking, and materials such as silver may be added to reduce odor and bacterial growth.
Compression running shorts are available through the Internet and in many sporting goods stores or running stores. Since they are considered specialty items, however, these shorts are not likely to be found in a general clothing store. Due to the importance of a good fit, some runners may prefer to purchase their gear in a person — where they can try it on — rather than online.