I don't run much myself.
There is the bone density issue that affect cyclists - if you sole ride bikes as exercise.

Once I watched a NHK tv show talking about various parts of the body and the bones were the theme at that time.
They talked about some promising american cyclist (don't remember his name) that fell on some neighborhood errand on rainy/wet evening and broke some hip bone.
Tests revealed his bones were very hollow with super low density.
Studies seem pointing/have found that to get stronger and bones with density it requires putting them under impact, like when running. So, it looks like the body learns that your bones don't need density if you solo ride bikes as your exercise.
Also, the tv show talked that bones are also used as kind of network in our body and with low density that feature get lost/reduced and can accelerate all the elderly deceases.