answer: #Person1# runs fast to burn up more calories. #Person2# tells #Person1# to burn up #Person1#'s fat, #Person1# must run slowly for a longer time.
documents: #Person1#: Come on, you are left behind!
  #Person2#: Wow, I can't catch my breath. You are running too fast, honey.
  #Person1#: You just need more exercise.
  #Person2#: Yes, but you need to slow down. This is jogging, not racing!
  #Person1#: I don't care. I want to burn up my fat.
  #Person2#: But running so fast is not good for people over forties.
  #Person1#: Why?
  #Person2#: We are not as athletic as we were when young. Mild exercise is more suitable for us.
  #Person1#: But I want to burn up more calories!
  #Person2#: In fact, in order to burn up your fat, you must take it slowly for a longer time.
  #Person1#: Really? I will slow down then.