X-Bionic Running Pant - Short
Here's what other sites are saying:
If you don't wear the proper clothing over your lower region during cool-weather activity then you could be wasting energy with every stride. You can lose precious body-heat in loose-fitting shorts while you run or you can wear the X-Bionic Men's Running Pant. X-Bionic uses technically-advanced materials in key regions to allow excess heat and moisture to escape and insulation material where you need it most.