I remind my son all the time of that fact that some people actually pay a gym to get the exercise we get for free but he doesn't seem to buy it. The whole process of heating with wood has to be one of the most rewarding pastimes around.
I told my son something similar after he asked me to buy him a gym membership(he's 13) i showed him how to split wood with the good ole 8lbs maul. He took right to it and after 2 or 3 nights of splitting some 46" hackberry stumps with a maul a sledge and some wedges he told me" man i have a lot more energy" my reply was that those tools are a but heavier than the PS3 controller he normally holds.