I would consider myself a runner if anybody asked me what sports I was into, however after a series of injuries mostly relating to ramping up distances and inadequate cross training I went out and bought a bike for the first time in years. I had a shock when I first went into a store and asked the salesperson how much a decent entry level road bike cost, and after adding on the hospital fees once my wife found out I opted for a second hand option (this has I admit resulted in me developing a new found passion for classic bikes but that's another story). the bike I bought was an 80's carbolite Peugeot, it is only a ten speed but seems fairly quick, my question is would I get a better endurance/aerobic workout with a higher geared bike or is this completely misguided thinking? Also whilst I know I am making my body (especially legs) work up hills and on the flats when I'm increasing cadence, I cannot seem to get the same level of cardiovascular exercise, am I just comparing chalk and cheese with riding and running or am I doing something wrong?