As a cyclist your knee is the main focus of all your power. If you develop knee problems, you've got a cycling problem. While you get lucky and never have knee pain during your cycling career, for most of us it will happen at some point. The key is to reduce the factors that lead to knee pain and treat is properly when it does happen so it doesn't become a chronic injury.
Follow these tips to help prevent knee issues and come back strong if you have them already.
Seat height and saddle fore-aft position will have a big effect on how much shear force there is on the knee. If you get pain in the front of the knee, you seat is probably too low or too far forward. If it is in the back of the knee, you seat is too high. A lot of pedaling with your seat in the wrong position can lead to over use injuries in the knee. Find a shop that specializes in bike fit to dial in your fit to reduce the chance of over use injuries due to bike fit issues.
Cleat and shoe setup
Cleat fore-aft position, angle and side to side position will change the angle the knee is getting loaded. Being a single plane joint, the knee has a very small window of angle side to side that is healthy and safe. As with bike fit this is best addressed by a professional bike fitter but here are a few tips to help you on your way. Cleats further back on the shoe will reduce load on the knee. If there is side to side movement of the knee through the pedal stroke, the stance width may to be adjusted or the foot may need to be adjusted for tilt with Lemond Lewedge shims.
Don't Over Do It
One you get off the trainer and get outside in the spring, you need to watch how much climbing you do. Once the weather warms up, it isn't unusual for a cyclist to over do it which can lead to tendinitis. Start conservatively and build each week in a progressive manor. Keep increases per week to 10%. If you have been riding an hour a day on the trainer, don't go out for a 3 hour hilly ride the first nice we get.
Joints need to be warmed up just like muscles do. Depending on fitness level you should warm up for 10-30 minutes. The fitter you are the longer the warm up you need. The first 5 to 10 minutes should be just easy spinning. You don't want to have hills at the beginning of the ride. Once you've gotten your breathing up a bit and broken a sweat then you should do a few harder efforts to activate the lactate clearing system and increase blood flow. Proper warm up will decrease the chance of over use injuries and get the body ready for harder work.
Clean up Your Diet
Most knee pain is caused by inflammation. Depending on what you eat, you can either increase or decrease inflammation in the body. Reduce processed carbs and saturated fats. Increase your intake of Omega 3 fatty acids, blue berries, strawberries, almonds, green tea, cinnamon, flax seed and extra virgin olive oil.