“I no longer run because it’s bad for my knees”.

 

We hear this in clinic ALL THE TIME.  Just know that if you come at us with this statement, be ready for a bit of pushback (more near the end of this article).

 

One argument that we generally will not debate is that cycling is a great option to stay in shape when you have symptomatic knee osteoarthritis.

 

In fact in our estimation, EVERY SINGLE PATIENT we have ever seen in the history of our clinic that is having a knee surgery for arthritis has been recommended cycling from their surgeon.

 

In general the thought is that cycling is a better risk/reward scenario versus running because there is no impact like there is in running when your foot hits the ground.  With cycling you still get the needed loading in your cartilage to help stimulate lubrication.

 

Yes you read that right.  You MUST load cartilage to ‘grease’ your joint.

 

In a horribly oversimplified statement that I’m willing to make, arthritis by its very nature is the degradation of cartilage in your joint.  As the cartilage thins and cracks it requires loading to allow it to produce lubrication like it should.

 

I do the lecture on knee osteoarthritis to the second year class at the Chiropractic College and here is a simple diagram showing what the degradation of knee cartilage looks like as it progresses:

 

 

 

An analogy that often gets used is that your cartilage is kind of like a sponge.  With no movement, the sponge will dry up and stop producing any fluid/soap.  But when you squeeze a sponge over and over that’s where the magic happens.

 

So we can all agree that cycling is likely a great activity for those struggling with symptomatic knee arthritis.

 

But this is starkly different than saying that cycling is actually GOOD for your knees and makes you less likely to develop arthritis in your knees to begin with.

 

Well a HUGE study from Baylor University just came out in April that makes an extremely strong argument that this may indeed be the case.

 

There is a massive ongoing data pool called the Osteoarthritis Initiative that is following thousands of adults both with and without knee arthritis over a 10 year period beginning way back in 2004.

 

From this data pool the world will glean lots of great information about one of the most expensive and debilitating conditions affecting the worldwide population (knee osteoarthritis).

 

For this particular dataset, the researchers looked at over 2,600 individuals who all had knee x-rays done, had knee pain, and importantly, filled out a questionnaire detailing their physical activity levels in 4 different periods of their lives:

• 12 to 18 years of age
• 19 to 34 years of age
• 35 to 49 years of age
• Over 50 years of age.

 

The main finding was really simple and can be described in one sentence.

 

Roughly half of the people reported some history of cycling and these folks were less likely to have knee osteoarthritis. 

 

Now if you are a reader of our material you likely know that there is actually a fairly poor correlation between x-ray findings for arthritis and how much pain someone is in.  It used to be that you required x-ray based degeneration to diagnose knee arthritis but over the course of time it’s been found that some people with severe changes on x-ray actually have minimal pain, while others with minimal changes on x-ray have severe pain.

 

Because of this, there are criteria for a kind of ‘clinical osteoarthritis’ that minimizes the importance of x-rays.

 

This study was great because they recognized this dilemma.

 

Instead of deciding that people required x-ray findings of knee arthritis, they used 3 different outcomes:

• Persistent knee pain
• Radiographic osteoarthritis (arthritis seen on x-rays)
• And ‘symptomatic osteoarthritis’ where you have both of the above.

 

It was found in this large sample that people with a history of cycling were:

• 17% less likely to have persistent knee pain.
• 9% less likely to have osteoarthritis on x-ray
• 21+ less likely to have both.

 

The other fascinating finding was that there was a ‘dose response’ to the amount of cycling people undertook.

 

Of the people that reported cycling, roughly half only cycled in one of the above mentioned four age periods, and it was most frequently the youngest (12-18 years of age).  BUT, with each ADDED age category (meaning cycling through 2, 3, or all 4 age categories) the likelihood of developing symptomatic osteoarthritis decreased…….BY A LOT!

 

In fact, if you cycled during 1 of the age periods, you had a 17% reduction in risk of symptomatic knee arthritis.  If you cycled during 2 of the age periods, this went up to a 19% reduction.  Cycling 3 periods saw a reduction by an incredible 28% and if you cycled throughout all 4 states of your life, you had a mind bending 43% reduction in the chance of developing symptomatic OA.

 

That’s insane.  43%!!!!!!

 

So what is actually happening here.  Can cyclists worldwide rejoice and throw shade at runners?

 

Not so fast.

 

Over time researchers always thought that knee arthritis was ‘mechanical’ in nature meaning repetitive or traumatic movements were required to produce the changes in cartilage that cause osteoarthritis.

 

More recently it’s been found that there’s a much greater factor involved.  In fact this factor is so important that in my lecture I spend about 15% of my time allotted on the research supporting how important of a risk factor it is for knee arthritis.

 

What is this mysterious risk factor?

 

Being overweight or obese.

 

And it’s not entirely just the added weight that people carry around slowly wearing away their knees.  In fact, some studies are showing that obese individuals have a greatly increased risk of developing arthritis in joints that have nothing to do with weight bearing like their hands showing that it’s not just due to the added load on their knees that causes arthritis.

 

It’s now being proposed that there is potentially some sort of whole body inflammation that may be triggering arthritis in these folks.

 

So then maybe the cycling has more to do with being in better shape and weighing less than the actual cycling itself.

 

Providing some credence to this is the fact that arthritis has been shown to be lessened in people that participate in swimming, running and strength training.

 

Yes I said it……running!

 

At the end of the day people have what are called modifiable and unmodifiable risk factors for arthritis in their knees.  The most important modifiable one by a landslide is trying to keep that excess weight off.

 

Now if you’ll excuse me I’m going to go hit the bike.