I began to run four days ago, 30-45 minutes at a very moderate speed. I'm eating atleast two hours before running, and my diet is clean. I began to have heartburn daily since my first run. Nothing else in my routine/diet has changed. Is there a correlation?

How old are you? About a year or two ago when I was 16ish I had heartburn from EVERYTHING. Anyways my doctor said it was common for young people to have heartburn, and said to just take some anti-acid (like tums) when the heartburn comes back. And going from heartburn everyday, now I can't even remember the last time I took tums. So it should go away. Just before you run take some tums with you. They taste horrible, but it helps. And you could always see a doctor :-)

thanks a lot for your reply, I'll take your advice and try the Tums!