Dev Mishra, M.D.
President, Sideline Sports Doc
Medical Director, Apeiron Life
Clinical Assistant Professor of Orthopedic Surgery, Stanford University
August 25, 2020
Lots of folks are using stationary bikes in their exercise-from-home routines. Overall, I’m a huge believer in their effectiveness and safety but offer some words of caution. If you’re someone with pre-existing knee arthritis or kneecap pain, you might make your knee pain worse when you focus on power by standing on your pedals.
Many types of knee pain are “load dependent”, meaning that if you increase load across your knee joint you’ll likely increase your knee pain. If you find yourself with more knee pain when you stand on your pedals, consider modifying your exercise to stay in the saddle and focus on a faster cadence.
Standing vs Sitting Creates Different Knee Joint Loads
We think of stationary bicycling as a low impact activity, and it definitely is when compared to other activities such as plyometric bounding or running downhill. But you might be surprised to learn that there are differences in the loads placed across the knee joint when standing on your pedals compared to sitting in the saddle.
Much of our knowledge of knee joint loads during stationary cycling comes from Ericson’s work in the 1980s, published in the Scandinavian literature. I recall learning back then that the best way to use a cycling ergometer while minimizing the chances of knee pain was to keep your RPM at 80 or higher. Decades later this remains true, in my experience.
Relatively recent work has confirmed many of Ericson’s original ideas. This interesting study by Kutzner and colleagues evaluated the actual forces inside a knee joint during various cycling conditions. One drawback of the study is that the patients all had total knee replacements so the mechanics are different than a native knee joint but the takeaway messages are these: “The lowest forces can be expected while cycling at a low power level, a high cadence, and a high seat height.”
Conversely, standing on your pedals such as you would with a hill climb is a very effective way to increase power output. But the mechanics of standing on your pedals does a couple of things that result in a higher knee joint load. First, you’ve added your body weight. In the saddle you only had partial body weight on your knees, when standing you’ve got all of it. Second, most cyclists will lean forward towards their handlebar when standing. This can place the body’s center of mass in front of their knee joint and this also increases joint load.
Peloton and Others Define “Low Impact” Cycling: Stay In The Saddle
Knee pain during cycling is something best avoided, so companies such as Peloton tackle the problem by offering what they call “low impact” cycling. On their blog they define low impact cycling like this: “Low Impact rides take place primarily in the saddle. The focus on this positioning helps to protect the rider’s joints, making it a more accessible class type.”
I will often stay in the saddle during my indoor cycling sessions and find that I can easily use a combination of resistance and RPM to get myself into a heartrate zone 4. It can be tough to maintain zone 5 in the saddle; you may need to come out of the saddle if that’s your goal.
Here Are Some Takeaway Points
Standing on your pedals is an effective way to increase power output. It can be easier to get into elevated heart rate zones 4 and 5 by standing, but it can come at the cost of increased knee pain.
An effective way to lower your chance of creating knee pain is to stay in the saddle. Use a combination of resistance and RPM to elevate your heart rate. I find that an excellent way to do that is to keep your RPM 80 or higher.