How much for a 6month old AB?? I take her out for long walks, rollerblading, dog park once in a while, she starts panting heavy so I stop and head home. 10-15minutes later its like she has not even started!!! Guess the real question is how long can you exercise them safely and know when to quit to prevent heat exhaustion (big con is living in south florida, which limits exercise to either early morning or late afternoon)