I love cycling. Wish I had a more time for it. But you need to diversify. Did you know if you get all your exercise from cycling you can loose bone density. Check this study if you are not familiar with this issue. Don't worry, it is not a big deal. It just means you have to add more variety to your exercise plans which is always a good idea. I like to hike, jog or use an elliptical for an alternate aerobic exercise.
It is also important to get some weight bearing exercises in. To be up front, I am a pretty thin guy. I learned my away around a gym but I always felt a little bit awkward there. Also being busy meant I would sometimes miss my trips to the gym. Then a trainer told me about body weight exercises. Rather that go to the gym three times a week, I use my body now every morning for ten minutes.
I started with a Men's Heath article on pushups. Here is a similar article. Basically if you start doing pushups everyday, you can go from nothing to get to your goal. This skinny guy is now doing 50 pushups a day.
Next I added chin ups. I was never any good at these. I could only do a few and seemed like it was really hard to increase my count. Then I bought a chin up bar with a giant rubber band assist. I use the assist to help me get more repetitions in. Then I scale back on the assist. Now I do twelve chin ups and twelve lat raises each day.
So there are some ideas to add weight bearing exercises to you routine. This will help you keep yourself healthy so you will be able to ride every more!