so i mainly use my bike for commuting, making a living (on occasion), tom foolery, etc. with the good fortune of getting unemployment for the next 6 months and going to grad school in 5 months, i have decided to get into shape and i figure my bike is a great way to do it.

anyway, what are your cardio routines? whats all this about target heart rate? how many minutes, how many days a week, etc.