Cycling training takes strength, endurance and stamina, which is strenuous in itself, but many cyclists seem to want to push it a bit harder and the knees take the strain.
As a result, the knee is the most cycling-injury-prone of all the joints.
Although racing or century rides can cause severe damage to the joint, most problems are caused in training, where the knee is often overused and abused.
Diagnosis of any joint injury is difficult even for a professional, but the knee can be a particular minefield. Do not attempt self-diagnosis of any joint injury; any prolonged knee problem should be looked at by a doctor.
But before you hit the panic button, it's worth remembering that most cycling-related knee aches, pains and poppings encountered by sports therapists are not the dreaded cartilage trouble, and sometimes the knee joint is not the problem at all.
Problems can arise from poor position on the bike, incorrectly fitted cleats, and in some cases, from the thigh muscles working excessively, especially on cold, wet or windy days.
At the end of a hard ride in such conditions, when the quadriceps muscles have been continually contracting and have become gradually tighter, you tend to get minor muscle pulls at the muscle insertions around the knee area.
If you use ice massage and quadriceps stretches, the condition often eases in a couple of days. If it persists, then seek qualified help.
Bursas are small fluid-filled sacs or cavities that are designed to prevent friction. They allow muscles and tendons to slip over bones and areas of ligaments. There are many bursas in the knee, and any of them may become inflamed through overuse doing too much too early in the season, for example or as a result of injury, especially falling on the knee; or because of an infection in the knee joint.