So I have been trying to get up before my kids go to school and do 30 minutes of cardio then when they leave I do 30 minutes of weights. I like to exercise outside so this has been working well. Yesterday I decided to sleep in. I pulled my three year old behind my bike for 45 minutes!!! I don't think I will sleep in again!!! Biking in this area....you are either going down or up a hill!!