Cycling is a form of aerobic exercise that is gentle on the knees. Unlike running, cycling is a low impact activity and places little pressure on the knee joint. However, this doesn't mean that cyclists are immune to knee pain. It's a common complaint, and should be taken seriously to decrease your time off the bike. If you experience aching knees, see a doctor or physical therapist to properly diagnose and treat it.
Aching Knees
When excess pressure is placed on the cartilage of the knee, it begins to break the cartilage down. This pressure is likely caused by a biomechanical abnormality, specifically of the femur, knee cap and the surrounding connective tissue. Extra pressure is placed on the bones of the knee as the cartilage wears down, causing pain. Because the knee constantly flexes and extends during the pedal stroke, this makes it vulnerable to pain.
Chondromalacia
One common knee injury in cyclists is chondromalacia. The knee is a ball and socket and cartilage makes up the padding and lubrication in the joint. When the cartilage is damaged, it can become inflamed. Lateral movement is often the cause. Weak quadriceps are usually to blame, as they control lateral movement. If you suffer from chondromalacia, pay attention to your pedal stroke, keeping it smooth, with no movement from side-to-side. Also, work on strengthening your quads.
Other Causes
Knee pain is often caused by a poor-fitting bike. Have a professional bike fitter assess your setup. He will take into account some of the triggers of knee pain, such as saddle height, cleat positioning and crank arm length. The weather can also cause knee pain. If you're riding when it's cool or raining, it's smart to cover your knees. Also, going too hard too soon in your training can strain the knees. Be sure to ramp up your mileage and hard efforts gradually to give your knees time to adjust. Try to spin instead of mash your gears.
Treatment
If you develop aching knees, stop riding and apply ice to the area. Rest and try to avoid activities that make your knee ache. Take anti-inflamatories and gradually ease back into cycling. When you ride, try to use gears that provide little resistance and work with a professional to identify the cause and treat your knee pain before it develops into a full blown injury.
