Exercise is very important for living healthier and longer lives. For people with obesity and osteoarthritis, exercise is even more important because it can help them feel less pain in their joints. Also, the more intense the exercise is, the larger the health benefits will be. The most common ways to exercise are running and riding a stationary bicycle. However, these two types of exercise can cause problems for people with obesity and osteoarthritis. Fast running creates large loads in the knees because of the impact of the foot on the ground. On the other hand, studies in cycling show limited improvement in pain because cycling does not allow the feet to move freely, which is important for reducing pain in people with osteoarthritis. This study introduces a new way to exercise using a hip flexion feedback system (HFFS). The subjects will exercise by increasing how much they lift their knees while walking on treadmill. The exercise will also involve controlling the impact of the feet on the treadmill. The HFFS monitors the subject's heart rate during the exercise using a standard heart rate monitor. A TV placed in front of the treadmill shows how high individuals need to lift their knees. How much participants need to lift their knees is calculated by the HFFS based on real-time heart rate readings. Therefore, the HFFS can help people stay at a specific exercise intensity by controlling how high it tells them lift their knees during the exercise. This study will have participants with osteoarthritis and obesity in two groups. One group will exercise using the HFFS. Another group will not exercise. The exercise group will do a 12-week high intensity exercise program. Our first goal is to determine how much fitness, pain, and the ability to move improve due to the exercise program. With this study we are looking to introduce a better and safer way to exercise for people with osteoarthritis and obesity. The results of this study will also allow for further development of home-based exercise and telemedicine.