Carbonfiberboy 

I don't rely on others for accountability in all the various corners of my life. In cycling, I ride instrumented, power and HR or just HR. I post every ride, walk, workout, hike, ski, etc., etc., on TrainingPeaks. It gives me a training stress score and keeps track of my accumulated training stress. I get a number. I try to keep that number increasing from October to August when I back off and let that number drop way off. During my long training period, if that number doesn't keep slowly going up, I'm not happy. I like to be happy, so I mostly stay with the program.

If you want riding partners who will make it more fun, you simply lead the ride. If they don't like your choices, find partners who will. I've found that most folks would rather shuck off responsibility onto someone else, so riding partners are not really that hard to find. You just have to be the responsible one and communicate with them, not that difficult. Having riding buddies who depend on you rather stiffens your spine.

To put it a little differently, I instrument myself in order to create a mechanism for accountability. If I weren't actually training, but just riding around, I wouldn't bother with the instruments. Many people prefer that, but I find that I stay healthier if I am accountable to myself and have a mechanism for that.

My wife and I both go to the gym and workout together, mostly twice a week for about an hour. There the accountability comes from our method: we lift to exhaustion, i.e. we know we couldn't do another rep. We keep those numbers increasing. Gym twice a week, they'll increase. Once a week and they'll just stay about the same, which is fine during the riding high season. It also helps that the gym is full of people just like us, so the positive atmosphere is helpful.