Ah, well, the older we get, the more important the "other" exercises are. I'm not a PT or MD, but I have a series of stretching and core exercises I do 5-7 days a week. They involve using a roller and a stability ball. I also do upper body lifting 2x a week and yoga 1-2x a week. Too much to explain here, but if you want more explanation, PM me.
I don't always feel like doing this stuff, but if I don't, I feel it. As you said, cycling can cause a lot of muscular imbalances. I also make myself walk or hike at least once a week during the cycling season and I'm beginning to actually look forward to the cold weather sports season, so my other muscles get some use.