You're probably right that I should try intervals. How long should these be, and how many should I do. I pretty much exclusively ride on bike paths b/c the city streets are crazy and have stop signs/lights everywhere. Of course, everyone else also rides on bike paths, so they tend to get very crowded - even when I get out before 6am. Therefore, it is hard to plan intervals. What I do is if the path is relatively clear and there is a slower rider somewhere ahead, I sprint to pass (then keep the pace up for a bit so as to not seem overly obnoxious). I'll also push myself hard to certain landmarks and then slow it down for a couple minutes to recover. But by doing this, my rides end up being essentially tempo rides with out any real, or meaningful, intervals. Also, I don't have a bike computer, so to really do interval training, I guess i need a stopwatch of some sort . . .