These are the most expensive running tights I've ever bought. They are also the best ones I've ever bought. My knees feel good when I'm done running! If I am going to be outside in the cold and standing up for a long time (such as when officiating at a track meet), then I wear these tights and I stay warm and I don't hurt as much. As a 37 year old recreational runner, these tights are so nice! I plan to buy the capri length ones to wear in the fall or late spring when the temperature is too warm for long tights but too cold for none at all. 5 stars