Maybe Arnold could get Furlong into shape
Arnold: John Conner, I've been sent back from the future to get you into shape.
Furlong: Yeah, who sent you?
Arnold: Your morbidly obese self from the future. In the year 2025, you develop type II diabetes, high blood pressure and are confined to a wheelchair. You send me back to help you lose weight in the present.
Furlong: Do I have to go running?
Arnold: Of course, it's part of the program.
Furlong: Do I have to give up doughnuts?
Arnold: Affirmative. They do not help our mission.