How does cycling impact your knees?

A big advantage of cycling is that it’s a low impact sport. This means it is easy on your joints attracting people of all ages. Repetitively spinning your leg over and over again takes its toll. Knee pain is the most frequent injuries in cycling, from professionals all the way to amateurs. So, how does low impact exercise cause this? In this article we explore some of the main causes of bad knees, and ways to fix them to keep you cycling.

Too far too quickly
Trying to do too much, too quickly can cause knee pain. The knee is supported by connective tissue. If you push yourself too much, by rapidly increasing your distance, speed or climbing, then you are putting added pressure on your knees. They will not be acclimatised to dealing with the added load. The result is inflammation of the knee, triggering pain. Just like building up muscles, you need to gradually let your knee joints get acclimate to the added load; only increase ride lengths or times by 20% when you first start cycling. Furthermore, always warm up which gets the connective tissue in your knees ready for load bearing; start out with each ride with gentle cycle at high cadence to get the blood flowing to your joints and muscles.

Poor fitting saddle
Having a bad fitting bike can cause all sorts of misgivings. Too long of a stem is bad for your back, however, for knee pain, the biggest culprit is saddle fitting. If the front of your knee is the problem, try raising the saddle a bit or moving it back in relation to the handlebars. If the back of your knee hurts, try lowering the saddle a bit or moving it forward a bit in relation to the handlebars. Imagine pedal motion is the arm of a clock; you can check positioning by placing your pedals in the 6-o’clock and 12-o’clock positions and rest your heel on the lower pedal. Your leg should be straight, which equates to a 20- to 25-degree knee bend when clipped in. When both feet are positioned parallel to the floor (3 o’clock and 9 o’clock), the forward knee should be over the ball of your foot.

If you find pain persists, we recommend getting a professional bicycle fitting. This will ensure you have a bicycle set up which puts you in the best position to eliminate pain.

Over Training
Cycling works specific muscle group, primarily quadriceps. If cycling is your main exercise, it is likely you have overdeveloped quadriceps and underdeveloped glutes and hamstrings. This imbalance can put pressure on your knees, which require an equal balance for support. Cyclists should rectify this imbalance; strengthen all muscles groups, by doing resistance-training exercises for all muscles in your legs, core and back. There are cyclist’s specific routines, and also tailored to specific goals, such as longer endurance or more powerful sprinting. British Cycling and Training Peaks are good resources to find a routine to support your needs.

Too high gear
A common mistake by cyclists, particularly those starting out, is to cycle in too high a gear. It often seems that a higher gear is faster. However a faster cadence in a lower gear is now considered better. ‘Mashing’ gears with cadence below 70rpm puts a lot of strain on the knee joint. The school thought is that higher cadence gives you better endurance as you rely more on the aerobic system, which can recover faster than the muscular system. A cadence sensor may be a useful training aid to help you understand correct cycling gears. This fits ether on the crank or wheel, with a computer display in the handlebar. This displays live cadence data during the ride, so you know if to change gear, and also post ride data to analyse your pedal habits.

Weak core
Core is not just about strong abs; your core, is actually group of muscles including abs, hip and glutes. These help stabilise and support body movements. The core supports riders in the saddle providing a platform to push off and balance. Over a long ride, just as leg muscles fatigue, so do core muscles. A weakened core results in less support and cyclist legs becoming lazy and moving side to side while pedalling.

It is important to train your core off the bike. You can find specific training exercises for cyclists, aimed at core strength. You should train your core at least once a week, and ideally when you have time away from the saddle to allow sufficient recovery.

Stretching
Throughout the pedalling rotation, leg muscles remain slightly contracted, and not at full stretch. Over time, this shortens the muscles and connective tissue, causing reduced flexibility. If you have poor range of motion, your pedalling may end up causing pain as your kneecap is unable to track in a healthy fashion. You can minimise this by doing a warm down stretch after every cycle. Additionally, foam rolling all leg muscles can keep legs feeling flexible. If you have long standing pain, getting a sports massage can help break any knots or tensions areas in your legs.

Pedal position
Where you put your feet on your pedals has a big effect on your knees. Cleats should be positioned so the ball of your foot is directly over or even a bit behind the pedal axle. Your cleat angles should be aligned with the natural angle of your heels, since unnaturally toeing in or out can stress your knees. Road cleats can also have float adjusted. This is the amount the shoe can move before unclipping; too little and the knee can be forced into painful positions too much float allows the knees to toggle all over the place which not only wastes watts, but stresses your joints. Nikola Innovation Pedals have taken this a step further with revolutionary ZIVO technology by allowing your legs and knees move in their intended position.

Feel free to give us a call or drop a note if you have additional questions or comments on your knee health.