Re group rides: The competitive aspect and the camaraderie make group rides addictive, at least for me. But it is easy to allow them to interfere with good structured training. You might go too hard on a ride when you should be doing recovery; you might be sitting in when you should be on the front stressing yourself. I have a coach who has put together a plan for me that incorporates group rides, with the expectation that I use them as race training.