Before we get started, I want to reiterate that most people have one dominate personality type and one (possibly two) secondary type(s). Even if you are an off-the-chart Lion or Otter, Golden Retriever might be one of your secondary types, so read on to see what you might can learn about that part of yourself.
In other words, a 3-month-old puppy will need 15 minutes of exercise while a 4-month-old will need 20 minutes. This may take the form of low-impact activities like swimming or playing with small dog exercise balls. You can also take your puppy out for short walks on a leash.
Yet as a general rule, Great Danes as a breed do not required excessive exercise. Over exercising a Great Dane is not recommended, especially with a growing puppy. Many Dane owners actually try to minimize Great Dane activity for their pup's first 18-months or so. Minimal exercise is typically enough to keep a growing puppy healthy and in shape. Over working a young dog during its rapid growth period can often have adverse affects on hip and joint development.