“My doctor said running is destroying my knees.” Many runners can relate to this same sentiment, heard in healthcare offices across the globe. But the fact is, running is a basic human function. Humans have literally done this since the beginning of time. We are born to run, by design and capability. Maybe you or someone you know has this fear that running is inherently bad for the knees and should be avoided. The truth is, when we look at the studies on runners, this view is simply wrong. Let’s dive into a little bit of that research and see how running truly affects the body.
So, what’s behind the notion that running is bad for your knees? Many see the continuous pounding your knees take when you hit the pavement as speeding up the degenerative process. However, this has not been shown to be the case. As we start to better understand the process of joint degeneration (otherwise known as osteoarthritis), it seems that being sedentary may be even more predictive of developing osteoarthritis than high-impact activities like running. In fact, as America has become more and more sedentary, osteoarthritis has become twice as common today as it was before the 1950’s. To make this determination, scientists at Harvard conducted a study looking at prehistoric skeletons as far back as 4,000 B.C. Many of the skeletons examined were from hunter-gatherer and farming societies, people putting a lot of wear and tear on their bodies and joints. Scientists expected to find a great deal of degeneration of their bones and joints. So, what did they find? After correcting for body mass and age, the studies showed that degeneration of the knee is much more common in today’s day and age. While this study doesn’t nail down the exact cause, researchers believe movement and physical activity have a very large roll in these findings. This makes a great deal of sense. The cartilage in your joints, including and especially the knee joint, lacks a direct blood supply. The way your joints get nutrients and remove waste is through the fluid surrounding the joint itself. Exercise and good quality movement helps the nutrients diffuse in and the waste diffuse out of your joints, keeping them healthy. However, as we have been leading more sedentary lives, we lose the opportunity to help keep our joints healthy: we’re not moving as much as we should. More movement is the key to less degeneration.
This research is great news for everyone, particularly runners. It reinforces what many have inherently known from doing it for so long- running and movement is good for the body and the joints. This is supported in the research specifically related to running and knee joint degeneration. One study compared X-rays from a group of runners aged 50-70 and a group of non-runners aged 50-70. Researchers found no acceleration of knee joint degeneration in the running group. Another study showed that the cartilage in your knees have the ability to re-grow, adapt, and recover after a hard run. Then there’s this awesome study from The American Journal of Sports Medicine. Researchers tracked a group of competitive runners starting in their 20’s, who ran an average distance of 12-24 miles per week for 40 years. They found no difference in joint alignment, range of motion, complaints of pain, cartilage thickness, and rate of degeneration in the knees. Researcher concluded, “Our observations suggest that a lifetime of long distance running at mileage levels comparable to those of recreational runners today is not associated with premature osteoarthrosis (joint degeneration) in the joints of the lower extremities.”
At this point, you runners may be thinking “It’s great that running isn’t bad for my knees, so why do they hurt?” Excellent question. Like any activity, sport, recreation, or hobby, we have to mindful with our approach. The research has also indicated the most likely factors for developing a knee injury while running. These include:
- Muscular imbalances around the joint (tight muscles on one side and weak muscles on the other).
- High training volumes. How many miles are you running per week? A sweet spot for most seasoned runners is around 30-35 miles per week.
- Previous knee injuries- a history of previous injuries makes you more susceptible to future injuries.
- History of medial knee pain (knee pain on the inside of the knee
- Physically demanding occupation
- History of knee surgery
- Lax ligaments (too much mobility in the joint)
These are just a few pieces of the puzzle that can contribute to knee pain while running, but running by it’s nature isn’t a bad thing. If you’re struggling with knee pain, give us a call at Inertia Health center and we’ll get you back on the road to pain-free running.