My BF and I ride together a fair amount, but when we "train" (hammer) together, it's usually a group ride, where he is having fun contesting the county line sprints and I am hanging on for dear life. He's really happy when I can hang with the big boys, though I'm usually suffering. But hey, cycling (well, racing) is all about improving one's ability to suffer, physically and mentally. So I do those rides, because they are good for me, and fun in hindsight . When we ride solo together, I can just get in the draft if he wants to work harder. Or, I'll let him fly up long hills and then we regroup. It can suck always feeling like you're just having to try to keep up, but at the same time, he says that I make him work hard too. For example, I'll want to hammer on descents and some fun, flat sections to reward myself for going uphill to get there. He likes climbing better. So, we're each stronger/faster/more motivated on different parts of the route and can challenge each other that way. If he really wants to train hard, like when he does his big sprints workouts with the area hammerheads, he goes alone, which is fine with me.