The paucity of clear training parameters for runners also has a knock on effect with a staggering 75% of runners report being injured whilst running each year with the knee being the most common region of complaint [2]. From my experience as a clinician, the factor that is most often associated with an injury are training errors. Too much too quick. Boom bust. No physical preparation. No listening to your body or allowing adequate recovery time. No periodisation or plan – just run and run.
The remainder of the talk that covered many interesting relatable topics (that will likely be areas for future blogs) but the information that most interested me and should answer the question as to whether running is bad for your knees was the following:
Cartilage change with running:
With the improvements in MRI scanning, more papers are looking at the cartilage volume of knees immediately after a long distance run. According to current evidence [3], cartilage may exhibit short-term decreases in thickness, volume and cartilage water flow (T2 relaxation time) secondary to temporary loss of fluid following repeated compressions associated with running. However, cartilage size tends to return to baseline within hours suggesting that cartilage may well tolerate mechanical loading sustained during running and adapt to repeated exposure.
The response of cartilage to longitudinal load is exactly what Van Ginckel et al [4] investigated. After providing a 10 week “Start To Run” program to novice runners, the reserachers looked at the glycosaminoglycan (GAG) content before and after the running intervention and compared to sedentary controls, who did no running. For those of you (like me) who had no idea what glycosaminoglycan / GAG content is, it is essentially a surrogate marker for cartilage quality (specifically, GAG is an important structural matrix compound in regulating the cartilage tissue’s endosmotic swelling pressure and thus, the tissue’s compressive strength).
The results suggested that a gradually built up running scheme appears to positively effect GAG content, and thus cartilage quality. In fact, running appears to be a chondroprotective effect on the knee when compared to a sedentary lifestyle in a female asymptomatic subjects. The author’s went onto say that running schemes like this might be considered a valuable tool in osteoarthritis prevention strategies [4].