When Cobain was younger and I was in high school, I did commit nearly 4-5 hours to working/exercising him almost every day.
High school was relatively easy for me, I only worked 12-15 hours per week (on weekends only), and had no expenses so I spent most of what I earned on dog classes.
There was a time where I would run him in the woods for an hour before school, then come home, another hour or so in the woods, fetch or frisbee for another 30-45minutes, tricks/obedience, then go to an agility class. Late after class we'd typically go for a quick walk around the block. Plus the acre yard that he has free access too.
I lived (and now live again) in a rural area with not a heck of a lot of people around. So my "social" options were limited to staying out at friend's houses Friday nights and that was about it.
Now, since my mother is more on board with the exercise, the dogs still frequently get at least 2 hours in the woods each day (usually I will take them, then she will later on), and it's not odd to get even 3 or 4 hours in one day depending on everyone's schedules.
Sun, wind, rain, snow...I'm out there - because let's face it, I need the exercise just as much as they do.
But the classes have pretty well come to a halt - except Rigby's obedience Wednesday night. Disc and fetch are becoming less frequent because I can't stand the hellspawn sounds that Ruby makes while the game is going on.
Either way, the house isn't destroyed, the dog's haven't gone insane, so I take it as a decent enough transition...
As for the "60 minutes being a low energy dog" thing, it depends on what that 60 minutes is doesn't it?
60 minutes of hard running compared to 3, 20 minute strolls around the block are very different amounts of exercise.