When horses feel safe, comfortable and have enough food and water to sustain them, their next need is stimulation. Your horse needs to be stimulated both physically and mentally on a daily basis. As with many other things when working with horses, you need to balance between the mental and the physical. You have to keep things interesting for your horse mentally and provide enough physical activity to keep him satisfied. One of my mentors, Gordon McKinlay, once told me that horses need three things: long rides, wet saddle pads and concentrated training in even doses. When those three elements are balanced, your horse benefits from mental and physical stimulation.