['Hey, have you ever ran a half marathon before?', 'I did, but not officially, and it was a trail running marathon(16 miles), how about you?', "I've never ran one before. I've been running at least 25 miles a week. Do you think i'm ready?"]
You are the only one who know answer to that.
I've ran 5 miles every other day for 5 weeks in preparation for my half marathon.