Molly is 5 months old and full of beans, she loves nothing more than a good tramp through the woods for an hour or so. At home she then has a drink and snuggles up for a good snooze - my question - is an hour too much for her at this age? Our trainer says she should only excercise for 5 minutes per month of her age, ie. 25 minutes and that any more could damage the development of her joints. I would hate to do any long term damage, would appreciate any tips you may have.