So how much cardio should you spend a week. I can spend all day in a gym, but never spend much time with the cardio. Is the main goal of cardio to just keep your heart rate up? I forget what your target rate should be, but isn't there a certin Target rate that should be maintain, What is the rate that should be maintained to lose the most potential fat. I am sorry, but I hate cardio and now that I am getting older I am relizing it is that much more important. Any little info will help, have a diet and workout planed, just need some input on cardio.