See my sibling comment. Repeated stress of right intensity makes bones, joints and tendons stronger. Avoiding all stress is a bad advice I have heard many time

See my sibling comment. Repeated stress of right intensity makes bones, joints and tendons stronger. Avoiding all stress is a bad advice I have heard many times in my life I am sick and tired of it. It is the stress that causes the body to need to recover and it is during recovery that it becomes stronger. The only really important thing to remember is that the right intensity is crucial and that it is very easy to suddenly overload a part of your body you have never even been aware of. Even a slight change in technique caused by something like different shoes or an aching toe can shift forces to places that are not ready yet and cause an injury. That's why good running technique is crucial -- because it is nothing else as a discipline to put your body through predictable motions in response to predictable loads. If you can do it you can now make sure your loads don't change too much over time and you should be relatively safe from injuries. Lots of injuries are caused by people running for longer duration but slipping with their technique because, for example, their core muscles get fatigued through the run. And this shifts loads to new places and causes things to get overloaded.