I don't find cycling to be very good exercise for me. I lived inner city and rode a bike everywhere for years. I don't have access to enough consistent bike path before I have to stop for crossroads (Djerring Trail). I like running because it gets my heart rate up and I can do it at the local footy oval. I could take my bike to Malvern velodrome but it makes exercise a three hour job with getting there and back.