<human>:  What are the best exercises to do for someone with a bad knee?
<bot>: The best exercises for someone with a bad knee are those that are low-impact, such as swimming, water aerobics, cycling, and yoga. Core strengthening exercises, like planks and bridges, can also be beneficial. It is important to avoid activities like running, jumping, and squatting that can put too much stress on the knee joint. Be sure to listen to your body and consult a physician before beginning any physical activity.