I know a recreational cyclist who did have problems because she was not getting enough impact. She was a long distance cycling junkie, about 5 days a week riding very long distances. But then again she may have had contributing factors. She is my mother's co-worker and is always advocating to my mom that I run. I do in the winter but in the hot months I mainly bike, some hiking. I agree with the quote, there is a probably a study to shoot this one down. I prefer mountain biking so I know there is more impact just riding than my road bike.
I still question if they are including risk factors in calculating this? Some people are going to be more likely to get osteoporosis for any number of reasons, not just because they are cyclists.
Amanda
2011 Specialized Epic Comp 29er | Specialized Phenom | "Marie Laveau"
2007 Cannondale Synapse Carbon Road | Selle Italia Lady Gel Flow | "Miranda"
You don't have to be great to get started, but you do have to get started to be great. -Lee J. Colan