i'm getting confused about how much cardio i should be doing to maintain my weight. i'm 5'3 and weight 120lbs. i keep upping my cardio to 5-6 days per week thinking more is better but notice that it makes me really tired. however i'm afraid of cutting down to 3 days per week (inbetween STS days) I have been using insanity for my cardio and on sts days i have been doing 30 min steady state. is this too much? for those that do 3 days of cardio, how's it working for you?