I'm somewhat new to the whole road biking thing and was curious about "pushing yourself" on the bicycle. I sometimes question whether or not it's good for your body to really work hard, and try and push your limits. At times the lactic acid buildup (when attacking a monster hill for example) is definately giving me the burn, and I notice that I can either push it, or simply lay off and give the body a break. I just don't know when working hard becomes damaging to your body. After a long ride I often find my legs are sore, sometimes even into the next day. I wonder if this is my body saying I'm pushing too hard. I'm curious what other cyclists think.