Does the dog need a leash or harness?
After about a week or two your dog should be able to run without the assistance of a leash. You do not need a harness of any type. The side rails keep the dog focused and positioned. Likewise, baiting the dog or over-encouraging the dog with toys will only break the dog’s concentration. The more distractions you eliminate, the quicker the dog will learn to use the machine. Once your dog understands the exercise, the dog will begin to lift his head and also begin to thoroughly enjoy the exercise.
