IAMAMRA, I ask this question and got some very thought provoking answers. One to consider is are there any local laws? Some states have a one year old restriction. Another consideration is the posibility of shaken baby syndrome. May not show up for years. I know there are some here that have done it from infancy with no problems but if not nec. why take the risk. Many foriegn country's like Dutch and Netherlands, this practice is probably common but with less danger from motorist. To me, it is no more than using a jogging stroller and jogging. Good luck with your decision.