I just started doing cardio and am going to start dieting hopefully Monday. I was told I should do an eliptical or stairmaster for 1 hour, 5 times a week. He told me not to jog because I would most likely burn muscle. Is this true? Also say I walked for an hour is that the same as running for a half an hour as long as I burn the same calories? Does it not matter the time but only the calories? What is the ideal calories I want to burn while doing cardio? Can I play any sports or anyting like that? If so is there a way to find out how many calories I burned? Thank you