You need to better explain what "intervals" you plan on doing. An interval can be anything from a 15" sprint to a 30' tempo effort. If you're getting dropped, chances are you need to raise your ftp (the max power you can hold for an hour). W/o a PM, you're probably better off avoiding zc intervals. Try 2*20' intervals once a week. Also see http://www.bikeforums.net/showthread...ut-recipe-book