Now, I am a believer that there is no substitute for running and if you want to get better, you need to run, but...
I am a high school runner who is doing nordic skiing to give my legs some rest after cross country, and I am also running 3 times a week. Between nordic skiing and the occasional long run I should be able to keep a relatively good aerobic system, however I am worried about losing leg speed (which I don't have much to of). So my question is, 1. Should I be doing some plyometrics to keep/build leg speed and if so, how often? And 2. What else, other then plyometrics and lifting should I be doing to build and keep leg speed?