Good Equipment
To protect the knees, the first absolutely essential point to look at is getting the right equipment. No matter what practice you are doing, the equipment you use will have a huge impact. Running is also the best example.
For example, the running machine from Home Fitness Code equipped with a smooth and ultra-quiet 1.5HP motor. Durable steel frame constitutes the treadmill's shock reduction & noise reduction system. The less noise makes the user run quiet and comfortable! More importantly, to protect user’s safety, 5 layer shock-absorbing belt with the characteristics of anti-slip and anti-static has been adopted, which tends to provide safe cushioning for user’s back, joints, knees, ankles, and muscles.
Lose Weight
This may sound strange, but weight loss is an effective way to reduce joint pressure. Whether in general life or in training, this is always good. No matter what you are doing, you are carrying too much weight, which will put pressure on your joints. Therefore, it is wise to keep your weight stable and healthy.
Don’t Overuse
Overuse of the knee can cause the irreparable injury to the knee. If you do too much exercise, it will eventually be harmful to your body. You'll feel worse and worse as time goes on and your joints ware away. This can also lead to various complications such as arthritis.
Overall, you will likely rely on your knees much more than you even know, so make sure that you’re taking care of them. If you feel uncomfortable, relax and try to exercise in ways that will not affect your knees temporarily.