There's no difference in my mind. Of course, I'm only a seasonal runner (winter, spring) and I have no issues running/hiking in my tights originally bought for cycling. I hate cycling tights with chamois, so it's great to have more than one use. I also wear them x country skiing, if it's really warm, like in the thirties (that's warm for nordic skiing). I've even run in my wool Ibex tights when it's been in the twenties.