There is no doubt that running is probably one of the best ways to improve fitness and health. It is easy to go for a run, it can be done at any time and probably almost anywhere and you can do it by yourself or with a group. The benefits are well known and well documented. However, there is a downside and that is anywhere between 20% up to 70% of runners get an injury each year (depending on how you want to state or manipulate the research). The main culprit for these injuries is probably just simply doing too much too soon. That is, increasing the distance and speed that you run at faster than the body can adapt to. TO avoid this you need to start slowly and build up slowly and give the body plenty of time to adapt to the increasing demands on it. there are plenty of blogs that discuss these issues.
Famous Words of Inspiration...
"To be happy, we must not be too concerned with others."