Sentence examples for a running from inspiring English sources

"a running" is not a correct or commonly used phrase in written English.
It's possible that you may have heard it used informally in spoken English, but it is not grammatically correct. If you want to use "running" as a noun, it should be preceded by an article or determiner, such as "the running" or "my running." Examples: - The running of the marathon was a huge success. - My running has improved since I started training with a coach.