since we are throwing out free advice here's mine... do not take any medical advice from anyone on any forum (this one included). most mean well but most are not doctors. if you don't like the advice of your doctor or are not in agreement with what he says and the articles put forth then get a second or third opinion. as others have said here, doctors can be wrong...but they can also be right.
fwiw, i ride as hard as i can as often as i can.