I have reached 1h 10 minutes of running, but inguinal pain showed up again.
At the moment I have suspended outdoor running and doing indoor strengthening exercises instead, mainly push-ups and light rope-jumping.
I have been inspired by Tejvan‘s comments on his cycling training to add stretching too.
Our spiritual Master advices to do more stretching, the older you are, the longer you should do. Even in his seventies, Sri Chinmoy had been stretching at least 2 hours early every morning as part of his dedicated routine.