“What makes these running clothes so special?”
At its core, running is a very simple sport with very simple equipment: all you need are two shoes and the clothes on your back. Yet despite this simplicity, or perhaps because of it, the wrong clothing can make running miserable. To make running workouts as comfortable as possible, specific clothing is designed to optimize the following properties.
No, a half ounce difference in the weight of your shirt won’t make a difference in your time. Heavier clothing will, however, generally be more resistant to movement and thus noticeable and, over the course of a long run, uncomfortable. Running clothing, then, tends to be thin, allowing it to freely move with your body.
Of course, for clothing to move with you, it needs to be at least somewhat close to you. There are two approaches to running clothing fit; which you use depends largely on personal preference. Form fitting clothing is designed to fit somewhat loosely and ‘float’ with your movements while minimizing actual skin contact, especially in high movement areas; form fitting garments excel in breathability and are more casually styled. Compression clothing, on the other hand, fits tight to the skin and actually applies light pressure to it, which can help promote blood flow and keep muscle groups aligned properly. In either case, the cut and seam locations are designed to avoid developing the hotspots that cause chaffing with physical activity.
Moisture Management and Anti-cling/Anti-static
Even if a garment is perfectly tailored to one’s body while dry, if any static electricity or water causes it to become tightly pressed to the skin, hotspots can still develop. Thus, running clothing is built from fabrics that have both antistatic and moisture wicking properties. The moisture wicking also helps keep runners comfortable by keeping skin dry. As a side note, cotton is avoided in running clothing as it absorbs sweat throughout the course of the run which leads to chaffing as well a very noticeable increase in weight and decrease in breathability. Bottom line: cotton is too cold on cold days, too warm on hot ones, and too hard on the skin in any running conditions.
Finally, running clothing is designed to look good and let runners work out without worrying that they might look ‘funny’. Most running wear makes for great multipurpose clothing that fits in at the grocery store, on the lawn mower, or hanging out at the local coffee shop or bar.