Four years old and training three hours a day

Take special note of this exchange in last night's ABC News piece about 4-year-old tennis player Mia Lines.

ABC News Correspondent:
"We hear about so many parents in sport, pushing their children, wanting them to be the best."

Glenn Lines:
"People might say three hours [of practice each day for a four-year-old], that's too long. A lot of parents [are] letting their kids play six hours of Play Station. Eating junk food. Drinking cans of soda."

Not sure what this establishes. Maybe that playing tennis excessively is less harmful than playing Play Station excessively.

Here's another TV piece on young Mia. (Thank you, Dirk Buikema).