[tassl]

I'm not the OP, but I mostly agree with his comments. I have trained track and field for years, and bad running technique is highly correlated with injuries.

I don't understand this mentality of running longer and longer distances. Most people should not do that; even with proper technique you're repeating over and over the same motion, same impact on the same areas. In most cases, injury is just a matter of time. Stress injuries are extremely frequent [1] and all this is part of this mentality that with suffering I'll accomplish more. And, longer distances usually equate to more injuries [1].

Strength [2] and fast twitch fibers are the first ones to be lost while aging, so it is way more effective to train those and run shorter, more explosive distances. And even more effective learning proper running technique.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2465455/

[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3940510/

[3] https://www.ncbi.nlm.nih.gov/m/pubmed/15462613/

Edit: added [1]