What is i cant keep up with my stallion duke?

As an AI language model, I don't have access to any specific information regarding your stallion Duke. However, if you are having trouble keeping up with him, it could be due to a variety of factors such as fitness level, age, or health issues. It is important to consult with a veterinarian and a professional trainer to assess the situation and come up with a plan of action. Additionally, regular exercise and conditioning can help improve your stamina and ability to keep up with a fast-paced horse.