I can just imagine Dad reading some CDC guidelines, or a handout from the pediatrician saying, "Your child should get 60 minutes of vigorous, supervised exercise daily..." Though probably well-intentioned, Dad is likely not instilling a love of activity, or a love of her body in Sally.
Have you ever watched a child on a swing? Do you remember how free, how powerful, how utterly in the moment and in your body you were? (See the photo of the boy top right.)
What Sally is learning is that exercise is not fun, it shouldn't feel good. Maybe she's learning that you exercise only so you don't get fat. What if she gets a little pudgy before puberty? How will that effect her self-worth? How will Dad react?
What we know is that pressuring kids to be active, just like pressure with food often backfires. Your job is to provide the opportunity for activity in a pleasant, fun setting. One of the most effective ways to get kids active is to limit screen time. They will come up with other things to do. Go for a walk after dinner together, have a scavenger hunt to look for leaves or listen to the cicadas. Ride a bike, head to the park, enjoy open gym time at the local rec center, and yes even swing on a swing.